I got permanently banned on my account, but it wasnt even me playing!!!!!

I was permanently banned on my account when it wasn't me playing on it and I had recently been banned for 14 days due to someone on my account so I went and changed my password because the person before hadn't changed it, and i went to work today and came back expecting to be able to play on my account but it was banned permanently because someone had played Lee sin on it and was toxic but it wasn't me. I have spent HUNDREDS of dollars on the game and I have done nothing to deserve this permanent suspension. Please help me!!!!!!!!!!

I have been banned before yes, I understand that and have accepted that. But leading up to the 14 day suspension. and this permanent suspension it has NOT been me playing. I did nothing wrong and have spent hundreds and hundreds of dollars on the game. I would have to think there is some form shape or fashion to riot having mercy on me when I did not do anything to deserve a punishment like I have. And if there is nothing they can do for me then they can at least refund me the money I spent on the game. which being the last time I spent money on the game was before the 14 day suspension. My reasons being

1. I didn't cause the permanent ban on my account.
2. I changed the password on my account after the two week suspension, and it still wasn't me playing.
3. I have put countless hours of time into this game and have made many friends, and too just ban me for not doing it and not refund me my money is completely and totally unfair.