Not able to use Spira Team Rest Web Service 5.0

Request Error

The server encountered an error processing the request. The exception message is 'Access is denied.'. See server logs for more details. The exception stack trace is:

at System.ServiceModel.Dispatcher.AuthorizationBehavior.Authorize(MessageRpc& rpc) at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage11(MessageRpc& rpc) at System.ServiceModel.Dispatcher.MessageRpc.Process(Boolean isOperationContextSet)

But when I tried only the get request for the service its working fine.

http://api.inflectra.com/Spira/Services/v5_0/RestService.svc?username=xxxxxxx&api-key=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx

I get the below response.

RestService Service

You have created a service.

To test this service, you will need to create a client and use it to call the service. You can do this using the svcutil.exe tool from the command line with the following syntax:

svcutil.exe http://api.inflectra.com/Spira/services/v5_0/RestService.svc?wsdl

You can also access the service description as a single file:

http://api.inflectra.com/Spira/services/v5_0/RestService.svc?singleWsdl

This will generate a configuration file and a code file that contains the client class. Add the two files to your client application and use the generated client class to call the Service. For example:

C#

class Test
{
    static void Main()
    {
        HelloClient client = new HelloClient();

        // Use the 'client' variable to call operations on the service.

        // Always close the client.
        client.Close();
    }
}

Visual Basic

Class Test
    Shared Sub Main()
        Dim client As HelloClient = New HelloClient()
        ' Use the 'client' variable to call operations on the service.

        ' Always close the client.
        client.Close()
    End Sub
End Class

I am not able to perform any get request apart from establishing the connection like above. Please help in pointing out what is going wrong here....