If they got it in last week than it for sure could have had mites; that's a very short amount of time to have a snake (and IMO too short to go right around and sell it without monitoring its health before putting it up for sale).
I would wait for details on the parents and see if you can get photos of them. I just really don't see pure Suri in this animal, even a low-quality pure Suri. She looks like she has too much Colombian influence to me, but we'll see if he can send you pics of the real parents. I personally would not send your snake back and would keep her and ask for a partial refund back. You paid $150 correct? IMO $150 is on the low end for a pure Suri, but if she is indeed a cross then I would ask for a partial refund of whatever would make you satisfied. If he agrees to that then you can wait it out for a real-deal BCC from a reputable breeder.