We'll see how far this goes, but it is a step at least.
https://forums.halowaypoint.com/yaf_postst155922p153_The-Official-Specializations-Email-Thread.aspx
Post by BS Angel in that topic. Reply on there. Her post:
While the original offer from Xbox states they will not re-send the codes, I'm still working with all involved parties to hopefully find a solution for those of you that were eligible for a code but didn't receive it (whether that's because you switched email addresses, accidentally deleted the email, etc.). Here is what you can do to help me with this effort:
Do not clutter this thread with non-constructive posts or spam. That buries the real information I need to assist you.
Post the following:
*Your Gamertag
*Confirmation you played the game while connected to Xbox LIVE before 11:59:59 P.M. Eastern Time on November 20, 2012
*Confirmation you are 17 years of age and older
*Confirmation you live in the United States, Canada, Chile, Mexico, Colombia, Brazil, Japan, Hong Kong, Singapore, Korea, Taiwan, Australia, New Zealand, or India
I understand this is a frustrating situation, and I will continue to work with Xbox LIVE on this issue. Please stay on-topic, so I can do that in an efficient manner. Thank you, and apologies again for the inconvenience.
ANOTHER BURIED UPDATE:Please do not post personal information on our forums. Confirmation should be given with a "yes" or "no". Thanks!