Gamestop- Arctic BR skin Stolen ?

Im a huge halo 4 fan and i was dissapointed when i reedemed the br skin.
It said sorry the code has already been redeamed. I called gamestop and they said It might be a bug. So i guys i dont know what to do im in panic.

Go to store, explain, they will generate you a new code. Bring your old code and receipt.

Either a bug or some bad luck. Either way, do as said above. Best of luck!

Alright thanks ill go straight after school tommorow .