Please don't feel badly. My Luna came from a pet store as well, and would have died if we hadn't bought her. My hubby insisted, though I knew about puppymills and tried to explain why it's not good to buy from pet stores, he wouldn't budge. After almost losing her and her being so sick and not wanting to eat and all, NOW he understands it

Of course, you were misled by the owner, but just think---you saved that baby, who may have ended up with someone that doesn't know how to care for these little ones as well as you do.