I think someone hacked my account and now I'm permabanned

Today I received an email saying I got permabanned for using 3rd party software. The problem is I haven't used anything so it seems strange. Then I checked my account in more detail and it seems someone has hacked it and played 3 ranked games, absolutely horrible at them too. I only play ARAM, you can see I have probably thousands of ARAMs in my match history. Now I have changed my password to something a lot stronger and I have submitted a ticket to Riot. Has anyone experienced something like this before? And could someone from Riot please help me out? Here is my match history for reference: https://matchhistory.euw.leagueoflegends.com/en/#match-history/EUW1/27222527 Last game I played myself was the Trundle one. I am interested in seeing the chat history from the ranked games. I feel bad for the people playing with the impostor so if any of you see this, I apologize for their behavior.
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