Apple ID Registered on School iPad?

Last year in highschool, we had started getting iPads at our school. I took one in a class and signed in on my account and downloaded some apps. I then signed out and removed the ID from the iPad. A year later, school has just started again (I'm going off to college though) and I just got an iMessage notification on my computer saying that my emails have been registered for use of iMessage & FaceTime on Cart 2 - 20. Is there a way to remove my accounts from that iPad? I don't want people having access to my personal info.