Hi @Gen3r4lC,
I'm sorry you got that response from them, that's not what I'd expect at all. On that DLC guidance link I put above, there is a contact email address for sold out, who handled distribution of the boxed version and all of the DLC codes. If you email them your details, they'll handle getting you the code since the retailer isn't being helpful.
Let me know when you've had the issue resolved.
Nat D11