I dont know why get banned???

I have Been Banned in Forza Horizon ,
I can`t do anything in my horizon
I forget how long i get banned(UNDER 1 YEAR AGO)
I think it is misunderstanding . Because I put my account to lend me a few friends to use…
Since then I have no online…After i online the forza Horizon want to buy a paint job in market just
say i got banned…But i don know why…can you unbanned me thanks>_<

My Xbox Live Gametag : By BlaCkNiGhT

Apologies for your frustration, however you should contact Turn 10 at forzafb@microsoft.com

Bans or enforcement of Xbox LIVE’s Terms of Use and Code of Conduct are not discussed on the forums.