Unban from ww1 pls

I don't know why I got banned. I didn't leave t2

Have you checked to see if it was a map ban or a host ban? If I were you I'd contact the host of that game you had. Incase it fails, I'd wait for another WW1 to pop up, hosted by a different player. However, if a host ban, you could either go to the Banlist Appeal Thread, here on the forums or talk to the mapmakers in question (Aetius and Pyrrhus, though they're inactive, so yeeaah)