how do i contact activision or submit a request to get my profile unbanned ?
The link I provided you clearly showed that Bans are irreversible.
Furthermore, you stated on your original post that this is not the first time you have been banned. Surely, you already know the consequences. Whatever it is you did the first time that got you banned, you did it again to get banned for the second time.
Claiming you got hacked will not change anything.
Own up to it.
You can contact them here - http://support.activision.com/pkb_Home?clickedOn=Black_Ops_II&uil=en_US
I am not sure if XBOX has a similar thing, as I am a PlayStation 3 gamer, but Sony have this option to "unlink" all PlayStation's that your account is logged in to, then you just sign in on your PlayStation once again and no other PS3's will be linked to your account. It may be worth contacting XBOX to see if they have something similar.
Hope this helps.