Best thing for you to do? Send an email to the game company itself. When Fileplanet bugged out and didn't actually send the WoW beta code, an email to blizzard got us a code. It wasn't a pain in the ass, we didn't need to even prove we had a confirmation page.
12 hours after it said the code was emailed, it was actually emailed- so we had 2 WoW beta codes. But it's possible that we would never have gotten the code, and I'm glad blizzard was reasonable.
Anyhow, you might want to forward your reciept to Mythic.