I had the same issue. My Gamestop had no clue. After doing a bit of online research, I found some people were getting codes, but only after making enough noise to the right Gamestop people. Others were told no pre-order DLC exists for the game. I just returned my copy and bought the game on PSN.
It's night and day. Vanilla NG3 was a total mess: funky lock-on that targets dead enemies; horrible, imprecise inputs. RE has massively improved the lock-on, and inputs now feel almost as tight as they did in previous games. RE essentially plays like NG2 at this point, although the soft lock-on is still off about 5% of the time compared to that game. In practise it's not a problem - the game gets it right when it matters - but you'll be surprised now and then in a crowd of enemies at moderate distance. So far, it's never been an issue at close quarters.
Honestly, playing RE is like listening to a cover band try to recreate music you know and love. But where NG3 was almost unrecognizable, RE retains the essenial elements of the original, and delivers something fans can enjoy. It's still a cover, and obviously so, but it's a great cover.