Consume a web service via WSDL url

I need to consume a web service using a wsdl url, after searching on internet, I generated a class library using wsdl.exe command-line, then made instance from the class and send parameter with object from the class but I am getting this error !!

Also I generated dll library from wsdl url and used it in a console project but I get the same error.

namespace ConsoleProject

{ class Program { static void Main(string[] args) {

        Services.Service obj = new Services.Service();
        Console.WriteLine(obj.MethodName("Param1", "Param1"));
        Console.ReadLine();


    }
}

}

the source web service is (Service.svc) and contains many methods.

What I am Missing !!! any help