Is there anything I can do to get my old account back?

I don't think so. :(

Ты can talk to Dave или contact fanpop.

After what happened earlier Ты don't deserve to get it back for being a cyber-bully.

Usually, there is a reason your account is banned. If Ты did something to deserve it then deal with it and don't come back unless Ты change your personality. However if Ты where banned by some immature person who reported Ты for having an opinion, then it's probably best to leave those kinds of people alone.
So no, there is no way to get it back, but people have already made that clear so...