Account Hacked

Send in a support ticket. Include any information that proves you are the owner such as the following;
E-mail you created it with, last good and working password and username for your account, answer to your secret question, if you don't know/remember your secret question have them ask it to you, any other proof that you can prove it is yours such as screenshots and replay's you may have saved, paypal or reciepts in which you bought zp for your account. The more of this information you have the easier it will be to get your account back.
Out of curiosity, you didn't fall for the zp trick did you man? I have two guys I have to turn in the screenshots on for trying this on me and it's gonna make me feel bad if it was one of them and I was too lazy to turn them in yet and get them banned.