I got banned as being a bot/account seller???

So, I made this account in July of 2017. But I haven't really played much until starting last month. Had a couple good matches, sucked other times. Parents made me stop what I'm doing to eat, or go places so I had to go Afk or disconnect. I understand that it's wrong to do. But I stopped playing for a while, and then I received an email telling me I've been suspended/banned today. "After an extensive investigation, this account has been detected as having been leveled by botting. This behavior is something that is usually associated with account sales and the use of third party programs, both of which are severe violations of our Terms of Use. Because of this, your account has been permanently suspended." Like, what the hell!? Though I'm new to the game, lvl 16. I ain't gonna have all that time I spent getting there go to waste.. If any of you go to my match record, you can see that all my matches are fair, failed some, did well some. As for third party programs, I've never used anything like that before. If I sold and made accounts to sell, I wouldn't be fighting for one account. I'm sure they'd have more than one account on hand, and they could always make more. But this is my one and only account, how could I be willing to just let it be banned?! All I want my account back, and to continue to play league. I don't want to start all over..