There is only one thing at GameStop that is not dynamically tracked and accessible at every store and that's pre-orders.
Are you sure you were at the correct store?
You must redeem your pre-order at the store you reserved it at. It is nearly impossible to lose that reservation information.
In response to loser employees taking your game, we have very strict policies on taking games home prior to street date. And the punishment for such a thing is severe resulting in termination.
Aside from that Game Advisors (GAs), who are non-managerial employees, do not have access to pre-release titles as they are generally locked within a cage that only managers can access.
To add another layer of security we do daily counts of pre-release games as we generally get them a few days early.
Return to the store, explain the situation to a manager and they should be able to print off a code for you.
I am not a spokesman I am simply a manager who has been with GameStop for 2 years.
They called the only other Gamestop in the area and asked them. No dice.
I really don't see the point in going to the store and speaking to the manager. He'll just look at the computer, see that there's no record of a preorder, and say "Touch luck." And I don't have a receipt for it so he could just also say I'm lying or something.
And no offense to you, but the guys who work at Gamestop are a bunch of dikes. The ones who work at this one are anyway.