The store didn't scam him, someone he met at the store did.

If you have this guy's name and where he lives you should probably pay him a visit. I really hope you did get some sort of bill of sale from the guy. It sucks that there are people out there like this but you also have to make sure you actually KNOW what you are buying before you plunk down money like that. IMO $350 is way too much for even a female pastel at that weight.