Original Poster,
Have you returned to other stores? Any stores? Not just video game stores?
Threre are now companies that keep customer return databases for retailers. Many retailers will sign up and they all submit their return information in to the database.
It works like your credit rating. I have read that some stores will check this database everytime you buy or return an item from them. If you show up with subpar rating they will refuse to business with you regardless. So, it is possible you did something someplace else (Victoria's Secret - return a pair of panties with skid marks will surely get you a bad return rating, McDonald's - return half eaten big mac will too I bet). Although, I read that this database is based off number of returns and not what is returned.
However, I think original poster is not telling the whole truth. Either stretching the truth, lieing, or just not giving details.
Chris