My wal mart has a pretty good selection of tanks, for not to expensive. Plus all the supplies needed. And they have a nice betta selection. I went to one petsmart and I couldn't find on healthy betta. DX
But yes wal mart is much cheaper, though I like buying deco from petsmart.
XD I'm not one for making big scenes. If the person didn't do anything, I'd ask for the manager, if the manager didn't do anything, I'd get my parents to back me, and if that didn't work, I'd probably file a complaint.