Can you please do something about the toxicity?

I just had someone in my game by the name of <removed by moderation>. This was a level 4 or so game, so nobody had smite. Two tops were called, the moment it was this person said they were inting if anyone else went top. They continued this into the game. I have a screen cap of them telling us they were going to int, and they can make it look not obvious. Clearly this person has done this before, over and over. They try to talk like they can work the system, and they try to incite counter bans for "toxic" behaviour as they ran headlong into enemies to feed. They had a duo with them, so come 15/20 minutes, both votes failed. We had to sit and wait out the other team BMing us and cheering the trolls on, as well as the trolls feeding and leaving me to try and Graves jungle without smite, and Kalista to try and solo bot lane. Can you please do something more permanent to this person than ban their "4th" account? Clearly they have little regard for punishment. The entire atmosphere of "I'm feeding so you can't enjoy" is what ruins this game, and yet people who trash talk (Weird competition, trash talk? THEY NEVER GO TOGETHER!) get nearly instabanned; but this kid gets to go on, tormenting everyone from level 1 to 30.