My Chat Ban

I just got a chat ban that I rly didn't understand why I mean if riot thought I was toxic at this game its fine with me but my problem is that I didn't show any sings of toxicity through the game or at least I didn't say anything bad compared to a Teemo that told me called me a lot of bad words and said a lot of things me and my friend reported him but I didn't see any signs oh him getting banned I am rly upset by this incident not because fo the ban I already accepted the fact that I wont get a victorious skin or a border at the end of the season but what made me angry is that was totally unfair this Teemo should be punished .Again if someone can help I wasn't toxic at any of my games at least not as much to get banned .Thank you