Mocking WCF Service with DI using Moq

I am writing some tests using Moq Framework. The application is build upon MVC pattern. I came across an issue and I seem to be stuck there forever. I need to write test for Service which code looks more or less this way:

    public class MyService : IService
    {
        private readonly IRepoInterface _inter1;
        private readonly Interface2 _inter2;
        private readonly Interface3 _inter3;

        public MyService(
            IRepoInterface inter1,
            Interface2 inter2,
            Interface3 inter3)
            {
                _inter1= inter1;
                _inter2= inter2;
                _inter3= inter3;
            }

       //there go methods
   }

What I basically need to do is check if foreach element from the string list of names of methods which IRepoInterface gets from DB, MyService's method invokes it.
I tried writing a builder (and I figured I don't need it, but now I am not sure), I tried simply mocking IRepoInterface list returning method in the initialization of my tests:

   List<string> methods = new List<string> { "method1", "method2" };

    Mock.Get(IRepoInterface)
            .Setup(x => x.GetListOfMethods())
            .Returns(methods);

This does not work (no method is invoked, test fails).
I guess my mistake is that I do not recreate dependency within MyService, since I mock IService and IRepoInterface separately, but at this point, as a newbie, I am totally confused. If you have any suggestions I'd be very grateful.