I know this is a bit late, but you have type the code in a Word Pad, or somewhere, and than copy and paste it into the redemption box. It should work. Make sure you are typing the correct letters and numbers. I was mistyping letters and numbers, so that is why it wouldn't work numerous times for me.
It didn't work for me.
Even when I put the GR bit before the code, every time I click "Redeem", the code comes up with a second GR before it. I don't get that =/
It's reaaaaally not fair D:
And... I just got blocked from trying again. =/ I really, really, really hope I'm not perma-blocked from trying to use the code D: