I got permabanned for nothing

Apparently, I've been using 3rd party programs, bots. For that I got perma-banned. I've never used a bot in my life, I've been playing this game for almost 6 years and never thought of using one. I mean I only just hit Gold by grinding up solo/duo queue. WTF! I just wanted to play the game, I haven't done anything to give myself an advantage or anything. The only thing I can think of is that I updated the permissions on all the programs on my PC last week since I was having to run everything as administrator. Could RIOT have thought that was me tampering with the client/launcher?

UPDATE: Somebody told me to check my match history. It looks like my account got hacked and somebody logged in as me yesterday when I haven't played in over two weeks.