I was banned a while ago for either my decals, or selling a certain car. so I read some of the other banned posts and it said to email forzafb@microsoft.com so I did. I got an automated email a few seconds later saying i cant email them because too many people do. All i want is to get unbanned. I even created a new save to play on without any of the bannable stuff.
That is the correct address to direct your enquiry. You should include as much detail as you can, including all Gamertags on the Xbox. Bans are not discussed on the forums.