I need help!?!?

I preordered halo 4 at my local gamestop but i preordered it online and the guy told me the preorder bonus content codes will be emailed to me so i kept checking my email the last couple of days and no codes have arrived. So i call my local gamestop today and i am told that i should have got my codes BUT not in my email but my powerupreward account on the website. I go and try to sign in on the poweruprewards website to see if i have the codes but i can’t login! It keeps saying i put it my information incorrectly, which i know im entering everything perfectly fine. Then i try to register but when i try to register it says my email is already on the gamestop network and that i could just sign in with my gamestop.com account but it wont let me login because of that stupid error! Please help i want my preorder content! =[

Somebody please help… =[