You'll need to contact the retailer you purchased it from; the retailer you bought it from is the one charged with giving you everything you paid for. If the retailer tells you that you need to speak with Bungie/Activision, then you need to ask to speak to someone higher up in that retailer, because it's their job, not Bungie's, to give you what you pay for. Bungie does not sell the game to people nor does Bungie hand out codes or replacement codes for lost/missing/non-working codes.