Why did i get chat banned

so recently I got chat banned for 10 games. when I looked at the chat log to see what I said and when I looked at it, it was from a game that I had never played. I logged off right after my last game right before it because it booted me off right after my game. I have been hacked. I have always tried to stay positive and support my team to win and rarely have I ever been toxic. I have tried to get onto the PBE and i'm afraid that I may never get on it now that I have gotten a chat ban. I have seen many other players be more toxic than I have ever been and I shouldn't have my chat ban. I just don't want this one chat ban on a game that I never played to effect my overall record.