How to return my custom class from my web api action

suppose this is my class which i like to return from my action

    public class Response
    {
        public bool IsSuccess { get; set; }
        public string Message { get; set; }
        public object ResponseData { get; set; }

        public Response(bool status, string message, object data)
        {
            IsSuccess = status;
            Message = message;
            ResponseData = data;
        }
    }

OR

    public class Response<T>
    {
        public bool IsSuccess { get; set; }
        public string Message { get; set; }
        public IEnumerable<T> ResponseData { get; set; }

        public Response(bool status, string message, IEnumerable<T> data)
        {
            IsSuccess = status;
            Message = message;
            ResponseData = data;
        }
    }

now this way i am wrapping output into response class and return from web api action

[HttpGet, Route("GetAll")]
public HttpResponseMessage GetAllCustomers()
{
    var Response=new Response(true, "SUCCESS", repository.GetAll());
    return Response;
    return Request.CreateResponse(HttpStatusCode.OK, Response);
    HttpResponseMessage response = Request.CreateResponse<Response>(HttpStatusCode.OK, Response);
    return response;
}

but json is not coming to client. where i made the mistake in code ?

i need to get json when i will invoke the above action from fiddler. please guide me how to fix the above code a result right json of Response class should return to client?

please give fresh and rectified working code copy of above one. thanks