I got banned by someone else who was on my account

The first thing you may want to do is go to account.live.com and change your password that way the other person will no longer have access to your account.

Secondly if you feel that you were suspended unfairly you would need to file for a case review at enforcement.xbox.com

The enforcement team is the only one that handles enforcement actions and the only Official way to reach them is through their website and the case review process. They do not monitor these forums.

Keep in mind that YOU are responsible for your account at all times. So if you give someone else your account information (say for game sharing) and they happen to get onto your account and do things that are not supposed to be done that is actually on you
because you gave that person your information.

I got banned for no reason all that happened was that I was in a challenge lobby in mw2 and then I got banned and says im banned until june 7 2014 and I was wondering if someone who works with Microsoft could help me get my account unbanned banned account
High Monk3y609

What should I do if someone else had access to my account and had broken the terms and conditions while using my account? Is it still my fault that my account got permanently banned?

Finally someone else who has my problem, mines a bit different tho, i was banned for 1 week then the next day banned for 2 weeks and if i go to xbox support it has no reasoning for the suspension

Dude exactly I got banned for a week then banned for 2 weeks the next day it sucks

I got perm banned aswell for someone using my account. the person was across the country from me and I told the enforcement to check and ips but no they simply ignored what I was saying and just explained why I got banned. like I already why I got an email
for it. what I was saying that it wasn't me who msged the person there was someone on my account. ive been trying to get my account back the past week but nothing. banning me for something I didn't do.