I've managed to have them do so before.
Ask for a new copy of the game, tell them that your cd is no good. They'll give you a new one that's sealed of course. They *might* open the new box first, in which case you're screwed and have to go through the process again, maybe at another store with a different person at the return counter
but if you do manage to get it replaced with a sealed copy, after that, go back with the receipt and return it sealed for a full refund. alternatively, if you see the same guy at the returns counter, maybe bring it to another store instead, like Best Buy and say you lost your receipt and ask for a gift card instead.. even better, just go to another Wal-Mart and you can use the receipt you have for a cleaner return process
This game stunk btw, I really didn't like it, grew old really fast