I think almost every pet owner made their first purchase from a petstore. Online searches have made it a lot easier to find clubs, shows and breeders, but not everyone looks there first, even nowadays. My first corn purchase was from a reptile & fish petstore. He had some kinks along his tail which they insisted was not something to be concerned about and would probably work itself out - he eventually lost movement in his tail and I've had to help with every single shed for the past 7 years.
Unfortunately, a lot of pet stores, even some of the small ones, are not as concerned with proper care as they have so many species to house and sell. It would be nice to hear for once a store acknowledging that they have a problem, thank the informer, and deal with their problem while helping the customer. Sadly, they'd rather deny the problem which in the end only fuels negative opinion. I think you'll be lucky to get a possitive reply from their head office, if you get one at all.
Though you're less likely to get an unhealthy pet from a reputable breeder or at an expo/show than at a chain petstore, there's always that chance. But you'll at least get better after care and support should the situation arise from a breeder that cares about their animals.
It sounds like you did the best you could for your little snow, and now you need to focus on giving your BP the best care and attention you can until you're certain he's healthy.