I've had similar things happen. This guy wanted to get 4 Oscars for his 20gallon tank, the Oscars were already about 3" each, I told him that one of those fish would out grow the 20gallon tank within 2 months time, what does he tell me? "oh don't worry about it, I've got a 75gallon tank for when these four grow fully" I called my manager over, explained the situation and we both basically begged the man not to buy the fish. He tells me he still wants them, I told him that I was sorry but that I wouldn't sell the fish to him. So what does he do? Calls my store manager over and explains to her that I refuse to sell him the 4 Oscars for his 150gallon fish tank! She asked if it was true and before I could answer my other manager steps in and starts yelling at this guy telling him how he told the two of us that it was a 20gallon tank and that a 75gallon tank would be the home for the 4 oscars full grown. My store manager kicked him out of the store and banned him HA!
Serves him right, man if I was you I'd of told the guy to get his own damn fish and I'd of gotten my manager. Sucks though, too bad for those fish... He loves his fish indeed... *shakes head*