Logged on for the first time in a year to a permaban

Hey, so this is pretty random but I was wondering if someone could give me a hand. I haven't played League in probably two years. At some stage last year I tried to play League again and so I contacted Riot support about getting my account back (because I couldn't remember some details about my account). I logged in but I don't think I played a game. Anyhow, I got the urge to play again today and so I updated the client and went to log in, only to find out I'm permabanned. There's also an email in my Inbox about it. Anyways, there's no explanation as to what I did to get the ban but the ban was apparently made a while after I got access to my account back but a very long time after I'd last played a game. It sucks because I have quite a number of skins. Any ideas why?
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