Aeria bans everybody now for these reasons:
1) Someoe reported you
2) You farm a lot such as LOCKDOWN farming
3) You play really well and have at least a 2 SD every game
4) You gained a lot of exp in a few hours
These are SOME of the reasons. I found these reasons in the Aeria forums. So if its not accurate blame the people in the Aeria forums. Even though you may not have done this Aeria will find some other reasonto ban you. Simple as that.
Aeria is stupid for banning people who never touched hacks in their life. Its a sad effort by Aeria to try to make the game "better".