I also tried to redeem my key but I get an error message.
I got the key by signing up to this website from here: http://www.zam.com/giveaways/nfsw.html
But when I try redeeming it with the link provided or on the NFSW homepage or even on Origin I get this error message:
There is a problem with the code you're trying to use. Please contact the Customer Support team.!
I contacted EA Origin Live support and they told me to contact the site that gave it away.