I bought Halo for limited edition console and I did not get the downloadable content that was suppose to come with it
Depends on how you bought. Was it used at gamestop? If so then you’re out of luck, DLC codes are [to my knowledge] never included with that stuff. If you bought the Halo 4 console new and didn’t get a code go through the official support resources of xbox.com. It’s a microsoft issue.