The worst thing you can do here is lie to us
We're not stupid.
We know Riot is constantly putting out warnings and chat bans.
We know you can't get banned for a one time offense unless you were so extremely toxic that it was worthy of a permaban.
We know that leaving one game is not going to get you put in low priority queue.
We aren't going to sympathize with you if you only came here to lie in hopes of getting pity.
If you really want help then you need to be honest with us.
P.s. If you genuinely don't know why you got banned. Go read your chat logs to your mother.