tactical enhancement pack

No and I find it extremely unlikely that they would ship the game with an invalid code. I've had a few folk tell me in the past that games have come with invalid codes and it turned out to be typos.
Mine worked just fine, be sure you are typing it in EXACTLY as it appears, by this I mean if its in upper case, type upper case, ditto for lower case. Likewise, if it shows hyphens between the code blocks(can't remember if this one does or not) then put in hyphens.

Out of curiosity, which format are you on? I'm on PC with Steam and its just a breeze to set up, apart from the slightly awkward method of registering the game on its own website. Sheesh, they make you work to find the registration page.