I hate seeing this kind of scenario.
Local shops within my area consistently house incompatible fish together, and it typically ends in fatalities. I stopped shopping at one of them altogether, even for dry goods, because they show a complete lack of of regard for the animals that they sell. In another, I have become an annoyance because I speak up and let the employees know which fish are getting bullied to death.
If I had the number of tanks for fish that I have wanted to bring home with me over the years, I may as well live on a boat because I'd have the ocean in my house.