I had this happen to an alt account I didn't even play on for a few months and had achieved nothing on but unlocked one legend. I logged on one day to find it banned for cheating. When I tried to dispute the ban I just got bot replies. They refused to provide any additional information or evidence.
I didn't cheat and I wasn't even playing on that account so all I can assume is that it got hacked. If not, then it's really scary to think what kind of criteria they use to determine what constitutes a ban.
All I can say is good luck with your account. Sadly, EA doesn't seem to do anything when you try to dispute a ban. They seem to be good at banning random accounts while actual cheaters are thriving on this game.
