diff --git a/Iyzipay.Samples/CardManagementPageSample.cs b/Iyzipay.Samples/CardManagementPageSample.cs
index bf94ce2..5b7b07b 100644
--- a/Iyzipay.Samples/CardManagementPageSample.cs
+++ b/Iyzipay.Samples/CardManagementPageSample.cs
@@ -30,7 +30,7 @@ public async Task Should_Initialize_Card_Management_PageAsync()
                 Locale = Locale.TR.ToString()
             };
 
-            CardManagementPageInitialize cardManagementPageInitialize = await CardManagementPageInitialize.Create(request, options);
+            CardManagementPageInitialize cardManagementPageInitialize = CardManagementPageInitialize.Create(request, options);
             PrintResponse(cardManagementPageInitialize);
 
             Assert.AreEqual(Locale.TR.ToString(), cardManagementPageInitialize.Locale);
diff --git a/Iyzipay/IyzipayResourceV2.cs b/Iyzipay/IyzipayResourceV2.cs
index e2d0e73..c5ec35f 100644
--- a/Iyzipay/IyzipayResourceV2.cs
+++ b/Iyzipay/IyzipayResourceV2.cs
@@ -4,107 +4,109 @@
 using System.Linq;
 using System.Net.Http;
 using System.Net.Http.Headers;
+using Newtonsoft.Json;
 
 namespace Iyzipay
 {
-    public class IyzipayResourceV2
-    {
-        private static readonly string AUTHORIZATION = "Authorization";
-        private static readonly string AUTHORIZATION_FALLBACK_HEADER = "AUTHORIZATION_FALLBACK_HEADER";
-        private static readonly string CONVERSATION_ID_HEADER_NAME = "x-conversation-id";
-        private static readonly string CLIENT_VERSION_HEADER_NAME = "x-iyzi-client-version";
-        private static readonly string IYZIWS_V2_HEADER_NAME = "IYZWSv2 ";
-        private static readonly string IYZIWS_HEADER_NAME = "IYZWS ";
-        private static readonly string COLON = ":";
+	public class IyzipayResourceV2
+	{
+		private static readonly string AUTHORIZATION = "Authorization";
+		private static readonly string AUTHORIZATION_FALLBACK_HEADER = "AUTHORIZATION_FALLBACK_HEADER";
+		private static readonly string CONVERSATION_ID_HEADER_NAME = "x-conversation-id";
+		private static readonly string CLIENT_VERSION_HEADER_NAME = "x-iyzi-client-version";
+		private static readonly string IYZIWS_V2_HEADER_NAME = "IYZWSv2 ";
+		private static readonly string IYZIWS_HEADER_NAME = "IYZWS ";
+		private static readonly string COLON = ":";
 
-        public String Status { get; set; }
-        public int StatusCode { get; set; }
-        public String ErrorMessage { get; set; }
-        public String ConversationId { get; set; }
-        public long SystemTime { get; set; }
-        public String Locale { get; set; }
+		public String Status { get; set; }
+		public int StatusCode { get; set; }
+		public String ErrorMessage { get; set; }
+		public String ConversationId { get; set; }
+		public long SystemTime { get; set; }
+		public String Locale { get; set; }
 
-        public IyzipayResourceV2()
-        {
-        }
+		public IyzipayResourceV2()
+		{
+		}
 
-        public void AppendWithHttpResponseHeaders(HttpResponseMessage httpResponseMessage)
-        {
-            HttpHeaders responseHeaders = httpResponseMessage.Headers;
-            this.StatusCode = Convert.ToInt32(httpResponseMessage.StatusCode);
+		public void AppendWithHttpResponseHeaders(HttpResponseMessage httpResponseMessage)
+		{
+			HttpHeaders responseHeaders = httpResponseMessage.Headers;
+			this.StatusCode = Convert.ToInt32(httpResponseMessage.StatusCode);
 
-            IEnumerable<string> values;
-            if (responseHeaders.TryGetValues(CONVERSATION_ID_HEADER_NAME, out values))
-            {
-                string conversationId = values.First();
-                this.ConversationId = !string.IsNullOrWhiteSpace(conversationId) ? conversationId : null;
-            }
-        }
+			IEnumerable<string> values;
+			if (responseHeaders.TryGetValues(CONVERSATION_ID_HEADER_NAME, out values))
+			{
+				string conversationId = values.First();
+				this.ConversationId = !string.IsNullOrWhiteSpace(conversationId) ? conversationId : null;
+			}
+		}
 
-        protected static Dictionary<string, string> GetHttpHeadersWithRequestBody(BaseRequestV2 request, String url,  Options options)
-        {
-            Dictionary<string, string> headers = GetCommonHttpHeaders(request, url, options);
-            headers.Add(AUTHORIZATION, PrepareAuthorizationStringWithRequestBody(request, url, options));
-            headers.Add(AUTHORIZATION_FALLBACK_HEADER, PrepareAuthorizationString(request, url, options));
-            return headers;
-        }
+		protected static Dictionary<string, string> GetHttpHeadersWithRequestBody(BaseRequestV2 request, String url, Options options)
+		{
+			Dictionary<string, string> headers = GetCommonHttpHeaders(request, url, options);
+			headers.Add(AUTHORIZATION, PrepareAuthorizationStringWithRequestBody(request, url, options));
+			headers.Add(AUTHORIZATION_FALLBACK_HEADER, PrepareAuthorizationString(request, url, options));
+			return headers;
+		}
 
-        protected static Dictionary<string, string> GetHttpHeadersWithUrlParams(BaseRequestV2 request, String url, Options options)
-        {
-            Dictionary<string, string> headers = GetCommonHttpHeaders(request, url, options);
-            headers.Add(AUTHORIZATION, PrepareAuthorizationStringWithRequestBody(null, url, options));
-            return headers;
-        }
+		protected static Dictionary<string, string> GetHttpHeadersWithUrlParams(BaseRequestV2 request, String url, Options options)
+		{
+			Dictionary<string, string> headers = GetCommonHttpHeaders(request, url, options);
+			headers.Add(AUTHORIZATION, PrepareAuthorizationStringWithRequestBody(null, url, options));
+			return headers;
+		}
 
-        private static Dictionary<string, string> GetCommonHttpHeaders(BaseRequestV2 request, String url, Options options)
-        {
-            Dictionary<string, string> headers = new Dictionary<string, string>();
-            headers.Add("Accept", "application/json");
-            headers.Add(CLIENT_VERSION_HEADER_NAME, IyzipayConstants.CLIENT_VERSION);
-            headers.Add(CONVERSATION_ID_HEADER_NAME, request.ConversationId);
-            return headers;
-        }
+		private static Dictionary<string, string> GetCommonHttpHeaders(BaseRequestV2 request, String url, Options options)
+		{
+			Dictionary<string, string> headers = new Dictionary<string, string>();
+			headers.Add("Accept", "application/json");
+			headers.Add(CLIENT_VERSION_HEADER_NAME, IyzipayConstants.CLIENT_VERSION);
+			headers.Add(CONVERSATION_ID_HEADER_NAME, request.ConversationId);
+			return headers;
+		}
 
-        private static String PrepareAuthorizationStringWithRequestBody(BaseRequestV2 request, String url, Options options)
-        {
-            String randomKey = GenerateRandomKey();
-            String uriPath = FindUriPath(url);
+		private static string PrepareAuthorizationStringWithRequestBody(BaseRequestV2 request, string url, Options options)
+		{
+			string randomKey = GenerateRandomKey();
+			string uriPath = FindUriPath(url);
+			string payload = request != null ? uriPath + JsonConvert.SerializeObject(request) : uriPath;
 
-            String payload = request != null ? uriPath + JsonBuilder.SerializeObjectToPrettyJson(request) : uriPath;
-            String dataToEncrypt = randomKey + payload;
-            String hash = HashGeneratorV2.GenerateHash(options.ApiKey, options.SecretKey, randomKey, dataToEncrypt); 
-            return IYZIWS_V2_HEADER_NAME + hash;
-        }
 
-        private static String PrepareAuthorizationStringWithUrlParam(BaseRequestV2 request, String url, Options options)
-        {
-            String randomKey = GenerateRandomKey();
-            String uriPath = FindUriPath(url);
-            String dataToEncrypt = randomKey + uriPath;
+			string dataToEncrypt = randomKey + payload;
+			string hash = HashGeneratorV2.GenerateHash(options.ApiKey, options.SecretKey, randomKey, dataToEncrypt);
+			return IYZIWS_V2_HEADER_NAME + hash;
+		}
 
-            String hash = HashGeneratorV2.GenerateHash(options.ApiKey, options.SecretKey, randomKey, dataToEncrypt);
-            return IYZIWS_V2_HEADER_NAME + hash;
-        }
-        private static string PrepareAuthorizationString(BaseRequestV2 request, string randomString, Options options)
-        {
-            string hash = HashGenerator.GenerateHash(options.ApiKey, options.SecretKey, randomString, request);
-            return IYZIWS_HEADER_NAME + options.ApiKey + COLON + hash;
-        }
-        private static String GenerateRandomKey()
-        {
-            return DateTime.Now.ToString("ddMMyyyyhhmmssffff");
-        }
+		private static String PrepareAuthorizationStringWithUrlParam(BaseRequestV2 request, String url, Options options)
+		{
+			String randomKey = GenerateRandomKey();
+			String uriPath = FindUriPath(url);
+			String dataToEncrypt = randomKey + uriPath;
 
-        private static String FindUriPath(String url)
-        {
-            int startIndex = url.IndexOf("/v2");
-            if (startIndex == -1)
-            {
-                startIndex = url.IndexOf(".com")+4;
-            }
-            int endIndex = url.IndexOf("?");
-            int length = endIndex == -1 ? url.Length - startIndex : endIndex - startIndex;
-            return url.Substring(startIndex, length);
-        }
-    }
+			String hash = HashGeneratorV2.GenerateHash(options.ApiKey, options.SecretKey, randomKey, dataToEncrypt);
+			return IYZIWS_V2_HEADER_NAME + hash;
+		}
+		private static string PrepareAuthorizationString(BaseRequestV2 request, string randomString, Options options)
+		{
+			string hash = HashGenerator.GenerateHash(options.ApiKey, options.SecretKey, randomString, request);
+			return IYZIWS_HEADER_NAME + options.ApiKey + COLON + hash;
+		}
+		private static String GenerateRandomKey()
+		{
+			return DateTime.Now.ToString("ddMMyyyyhhmmssffff");
+		}
+
+		private static String FindUriPath(String url)
+		{
+			int startIndex = url.IndexOf("/v2");
+			if (startIndex == -1)
+			{
+				startIndex = url.IndexOf(".com") + 4;
+			}
+			int endIndex = url.IndexOf("?");
+			int length = endIndex == -1 ? url.Length - startIndex : endIndex - startIndex;
+			return url.Substring(startIndex, length);
+		}
+	}
 }
diff --git a/Iyzipay/RestHttpClientV2.cs b/Iyzipay/RestHttpClientV2.cs
index b8c9e82..bb6a0ec 100644
--- a/Iyzipay/RestHttpClientV2.cs
+++ b/Iyzipay/RestHttpClientV2.cs
@@ -6,6 +6,7 @@
 using System.Net.Http.Headers;
 using System.Linq;
 using System.Threading.Tasks;
+using System.Text;
 
 namespace Iyzipay
 {
@@ -64,11 +65,12 @@ public T Post<T>(String url, Dictionary<string, string> headers, BaseRequestV2 r
 		}
 		public async Task<T> PostAsync<T>(String url, Dictionary<string, string> headers, BaseRequestV2 request) where T : IyzipayResourceV2
 		{
+			var content = new StringContent(JsonConvert.SerializeObject(request), Encoding.UTF8, "application/json");
 			HttpRequestMessage requestMessage = new HttpRequestMessage
 			{
 				Method = HttpMethod.Post,
 				RequestUri = new Uri(url),
-				Content = JsonBuilder.ToJsonString(request)
+				Content = content
 			};
 
 			foreach (var header in headers)