Why am I being banned for nothing?

So I am your average LoL player. Get on, play a few games, get off. I rarely ever get into a heated discussion with another player nor do I ever try to be mean to anyone. I am the guy who would screams at the screen rather than take it out on my teammates. I have now just got a report that I have been perma banned for reasons I can't figure out. At first I thought it might be a charge back, but when I checked the riot repay website it said I had no debt. I looked at the email and I see that I had no ticket which is what I thought you get for being banned by the tribunal. I really do enjoy this game which has given me so much and I just at least need to know why I got banned. Please and thank you.