Halo 4 Walmart in store preorder card help

I went to Walmart to preorder halo 4 and when I got it it said that i go to zreward.com to redeem and get the circuit armor skin, but it keeps saying invalid? Will it be available to use on Tuesday when the game is out?

Where is the link to the .37 cent code and do you have to pay for the game in full to get the armor.

Idk i didn’t get it fr the link I went in store and put 5 dollars into the card. Question is will I be able to use it on Tuesday?

hopefully i will be able to because as far as ive heard, the people getting the emails confirming their codes have been people that have bought it through the walmart.com site