This is a great company to work for.
The only thing I can think of (because something similar happened to me).... (not with QAMS) ....was that your shop was disqualified. This may or may not be the case for you. But it was for me. But with some corrections I was paid after clarifying something.
I would simply call and ask. It could be many things. A fluke in the computer. Or, as I said, perhaps your shop was disqualified but I am only guessing.