HttpWebRequest request = (HttpWebRequest)WebRequest.Create("https://accounts.zoho.com/oauth/v2/token?refresh_token={refreshToken}&client_id={client_id}&client_secret={client_secret}&grant_type=refresh_token");
        request.Method = "POST";
        JObject requestBody = new JObject();
        JArray recordArray = new JArray();
        JObject recordObject = new JObject();

        recordObject.Add("First_Name", contactData.FirstName);
        recordObject.Add("Mobile", contactData.PhoneNumber);
        recordObject.Add("Email", contactData.Email);
        recordObject.Add("Kategori", contactData.MessageType);
        recordObject.Add("Konu", contactData.Subject);
        recordObject.Add("Last_Name", contactData.LastName);
        recordObject.Add("Company", contactData.CompanyName);
        recordObject.Add("Sirketiniz_ile_ilgili_ozet", contactData.CompanySummary);

        recordArray.Add(recordObject);
        requestBody.Add("data", recordArray);

        string dataString = requestBody.ToString();
        var data = Encoding.UTF8.GetBytes(dataString);
        int dataLength = data.Length;
        request.ContentLength = dataLength;
        using (var writer = request.GetRequestStream())
        {
            writer.Write(data, 0, dataLength);
        }
        request.KeepAlive = true;
        HttpWebResponse response;
        try
        {
            response = (HttpWebResponse)request.GetResponse();
        }
        catch (WebException e)
        {
            if (e.Response == null) { throw; }
            response = (HttpWebResponse)e.Response;
        }

        HttpWebResponse responseEntity = response;
        Console.WriteLine("HTTP Status Code : " + (int)response.StatusCode);
        string responsestring = new StreamReader(responseEntity.GetResponseStream()).ReadToEnd();
        responseEntity.Close();
        Console.WriteLine(responsestring);