I'm not surprised.
What you do is, next time you happen to be in EB Games, just "casually" mention to one of the clerks (or preferably the manager)...
"Hey, Mario Power Tennis! Y'know, I actually wanted to buy this game a couple days ago, while you had that Midnight Madness thing, but you refused to sell it to me because of some "Halo only" thing, so I bought it the next day from [insert competetor here]."