take it back. they should exchange or refund. if they say no, tell them to watch the forums!

you do need to be SURE though. is it PM or mold? was it damp? does it smell moldy?

do you have a half decent digital camera w/macro?

I wouldn't post anything bad about anyone without pictures.

mold can happen to anyone and they may not even know it. It's all about how they deal with fixing the situation.