How long until these Ebay bronze smurfs get removed from ranked?

Continuously run into last/current season 'plat' players who now have a 45-35% win rate with 200-600 games with a low gold- mid silver MMR? What are you going to tell me, they're having a bad season? Lmao, they just dropped 2 teirs of brain level cause new season??? Lol..... What a joke. These people are 90% toxic straight from select, and still not banned 300 games in, oh BUT DONT SAY %%%%%% THOUGH!!! That's instaban!