So someone got on my account and prestiged me.

So today i hopped on xbox and there was a message that said someone had got on my account from another xbox. I shrugged it off. I played some Black Ops zombies for a while then decided to play MW3. When I got to the Multiplayer menu, it had me as Prestige 1 level 1 when just last night I was Prestige 0 Level 80. I don't this and I was wondering if anything can be done and who I should contact. I already talked to a guy for Activision who said he couldn't do anything except maybe I should tweet InfinityWard. Well i did and there's still no reply.

TL;DR Someone got on my account, prestiged me. What can be done/ who should i contact. Thanks