What can i do if i got banned because my account was hacked?

Actually, this ban doesn't exactly have much to do with EA, as it came from Punkbuster, which was created by Evenbalance (thus making PB a third party program). The only connection to EA is that Punkbuster is used in many EA-published games, such as Battlefield 3 and 4... but it also finds its use in many other titles developed/published by major companies. Heck, I remember that it already was in use when I have played the first Call of Duty, back in 2003. Basically, if anything, you shold be upset at Evenbalance...