Unfairly banned

Hey guys, On Thursday I logged on for a game before Uni and after I chose my champion I was alerted to a message that I had been banned. The email I received said I had been permanently banned for the use of a third party program. I have used a custom skin changer in the past, other than that I have no idea what the reason would be. I have received two responses from riot: https://gyazo.com/00c63f5550c0e9d7840996f5a21450f6 https://gyazo.com/39890c9628de270bb055cab21a79f4d3 So I am getting told I was caught using an exploit, when I know for sure I haven't been. I have had my account since early 2012 - not something I would ever risk for something so stupid. Has this happened to anyone else before? And more importantly does Riot ban users permanently and without warning for a custom skin changer.
Report as:
Offensive Spam Harassment Incorrect Board