12 Month Problem From Dumb Brother

I just logged on to cancel my WoW subscription as I now longer have time since I'm starting senior year at college only to find out that I've been locked in to the 12 month commitment. I have found out it was actually my little brother who took my authenticator and signed me up because we were talking and I'd expressed interest in possibly doing it. I guess he thought he was doing me a favor. I obviously did not get to read the specifics of this contract, but for those who have, am I liable for this and can it be removed from my account so I can cancel?