I don't think we got the whole story. Resorting to fisticuffs over a merchandise return doesn't make sense. I suspect the customer did some major damage to the goods that made them unfit for resale.
Back when I was younger you could go in and talk to the salesmen and they could actually give you good advice after putting down their soldering gun. Usually someone was in the rear testing some vacuum tubes they had brought from home. They should change the motto to “Radio Shack....you got questions? We got questions”!