WCF REST WebInvoke POST returns bad response - vb.net

Question

May anybody help me I am tired of doing all the thing, but service returns bad return if string length exceeds more than 10000 characters.
Thanks.
This is my .svc file:
<%# ServiceHost Language="VB" Debug="true" Service="BPMMobile"
CodeBehind="~/App_Code/BPMMobile.svc.vb" Factory="MyServiceHostFactory" %>
My contract:
<OperationContract()> _
<WebInvoke(UriTemplate:="/SaveData?
Data={Data}", BodyStyle:=WebMessageBodyStyle.Bare, Method:="POST", ResponseFormat:=WebMessageFormat.Xml)> _
Function SaveData(Data As String) As String
Here is my web.config file:
<system.serviceModel>
<bindings>
<webHttpBinding>
<binding name="MobileBinding" maxReceivedMessageSize="5242880">
<readerQuotas maxDepth="32" maxStringContentLength="5242880" maxArrayLength="16384" maxBytesPerRead="4096" maxNameTableCharCount="16384" />
</binding>
</webHttpBinding>
</bindings>
<services>
<service name="BPMMobile">
<endpoint
behaviorConfiguration="webHttp"
binding="webHttpBinding"
bindingConfiguration="MobileBinding"
contract="IBPMMobile" />
</service>
<service name="DMSService">
<endpoint
behaviorConfiguration="webHttp"
binding="webHttpBinding"
contract="IDMSService" />
</service>
<service name="ImportMaster">
<endpoint
behaviorConfiguration="webHttp"
binding="webHttpBinding"
contract="IImportMaster" />
</service>
</services>
<behaviors>
<endpointBehaviors>
<behavior name="webHttp">
<webHttp />
</behavior>
</endpointBehaviors>
<serviceBehaviors>
<behavior name="">
<serviceMetadata httpGetEnabled="true" />
<serviceDebug includeExceptionDetailInFaults="true" />
</behavior>
</serviceBehaviors>
</behaviors>
<serviceHostingEnvironment multipleSiteBindingsEnabled="true" />
</system.serviceModel>`
Here is my Custom service host
Public Class MyServiceHost
Inherits WebServiceHost
Public Sub New()
End Sub
Public Sub New(singletonInstance As Object, ParamArray baseAddresses As Uri())
MyBase.New(singletonInstance, baseAddresses)
End Sub
Public Sub New(serviceType As Type, ParamArray baseAddresses As Uri())
MyBase.New(serviceType, baseAddresses)
End Sub
Protected Overrides Sub OnOpening()
MyBase.OnOpening()
If MyBase.Description IsNot Nothing Then
For Each endpoint In MyBase.Description.Endpoints
Dim transport = endpoint.Binding.CreateBindingElements().Find(Of TransportBindingElement)()
If transport IsNot Nothing Then
transport.MaxReceivedMessageSize = 5242880
transport.MaxBufferPoolSize = 5242880
transport.MaxBufferPoolSize = 5242880
End If
Next
End If
End Sub
End Class
Class MyWebServiceHostFactory
Inherits WebServiceHostFactory
Protected Overrides Function CreateServiceHost(serviceType As Type, baseAddresses As Uri()) As ServiceHost
Return New MyServiceHost(serviceType, baseAddresses)
End Function
End Class
Public NotInheritable Class MyServiceHostFactory
Inherits System.ServiceModel.Activation.ServiceHostFactory
Public Overrides Function CreateServiceHost(constructorString As String, baseAddresses As Uri()) As System.ServiceModel.ServiceHostBase
Return MyBase.CreateServiceHost(constructorString, baseAddresses)
End Function
Protected Overrides Function CreateServiceHost(serviceType As Type, baseAddresses As Uri()) As System.ServiceModel.ServiceHost
Return New MyServiceHost(serviceType, baseAddresses)
End Function
End Class