I would call the 888-BEST-BUY number. Tell them you never got your code and they will transfer you the the digital redemption dept. After I talked to them, I had my working code in about 2 hours! Hope this helps!
It seems lately I only receive half of my preorder codes. I never received my Jak & Daxter code with my Lost Legacy preorder. But this debacle takes the cake. I immediately contacted Gamer Support via emial and nothing. Waited and waited. Then many people used two more codes for the full game. I got nothing. Still waited. Then we're told that correct codes should be arrivong in our emails righy away. Yup, still nothing.
I probably spend over $10k per year at Best Buy, but I'm getting a little tired of this crap. I've never had an issue with preorder bonuses from Amazon for instance.