Maybe the MSC thinks that the reason that you are not getting paid is obvious. Maybe there is another reason, or reasons. I have only been shopping for about a year now. If you honestly do not know why or if you can't figure it out and assuming that you are a reasonable person, I would be more careful about the MSCs that I shop for and the shops that you do. I learned this lesson very early. I still have problems now and then, but not frequently.