For those who work with AX 2012 AIF services and try to call there C# or VB project inside AX (x++) and suffer from such errors of "could not find default endpoint"... or "no contract found" ... go back to your visual studio (c#) project and add these lines before defining your service client, then deploy the project and restart AX client and retry: Note, the example is for NetTcp adapter, you could easily use any other adapter instead according to your need.
Uri Address = new Uri("net.tcp://your-server:Port>/DynamicsAx/Services/your-port-name");
NetTcpBinding Binding = new NetTcpBinding();
EndpointAddress EndPointAddr = new EndpointAddress(Address);
SalesOrderServiceClient Client = new SalesOrderServiceClient(Binding, EndPointAddr);