You will never be unbanned
The amount of toxicity that it takes for you to get to the point where Riot decides they don't want you around anymore is a very fine line, and it's further away from normal behavior than you want to force yourselves to think. When you force yourself to autotilt, sabotage games by intentionally feeding or going AFK, and scream racist obscenities in the allchat (and I mean SERIOUS racism), you are well beyond that line.
You won't get your account back because you claim to have reformed or because you have spent some $2000+ on the game. The amount of money you've spent on the game is not insurance against your own douchebaggery. If that's the cost of you learning to control yourself, then so be it. You are in control of your own actions; muting yourself will not stop you from sabotaging games or forcing yourself to autotilt over the tiniest things.
Don't try to argue the point to support your own toxicity. I've heard every possible argument you could fabricate more times than any of you will ever hope to dream to be able to count.