Thanks for the tip also, MidValley. Not going through for me at the moment. Will keep trying. Gives me a Please Try Again Later error.
Just came through. Ok, I had already preordered it at gamestop so I already have the challenge, but it said that to get the stuff I won in the challenge I would need a 2nd code? Can I redo it with this and get my items? Not sure how to get the followup code to redeem what I earned.