I have 1 good story and 1 bad. I'll start with the good.
The petco near me seems to take really good care of their bettas, the are really the only pets they have in the store. One guy who works there seemed genuinely interested when i was telling him about my 2 and even offered to give me a free female since they get bought less and he hates seeing them in he store for a long time. He'd set up a hospital station next to the sink to treat the sick ones when they came in and the water is lovely and clean. He also told me that if a fish stays int eh store too long he takes it home with him. His house must be packed!!
Onto petsmart... i saw my current male Igor lying on his side in a dirty cup struggling for life, with ripped fins and bad finrot :( I picked him up and took him to the cashier and mentioned in passing that he had finrot, she took the cup from me to have a look and said "i best go show my manager", he didn't come back out with her. They took him into the back room and told me he'd be treated for the fin rot. I thought for sure i'd lost this fish, that he'd be killed or just left out there to die. Luckily for me the employees at this petsmart are clearly morons; i went back later in the afternoon to find a new supply of pretty flashy bettas in the shelf, and Igor shoved right to the back, hidden behind everyone else. Needless to say i snatched him right up and bought him. He's doing awesome now!!
I don't shop in that store anymore. I chose not to give them anymore of my money, instead i shop at the petco, which is smaller and has less options but at least they care for the animals there.