How to deal with inters and toxic people?

The problem is that 2/3 games I get at least two people trash talking and spending more time on the keyboard rather than the game. I've been in platinum 2 for quite a while because in every match someone is too preoccupied to curse the entire team and not paying attention to that game. In most cases, that person has a score of 0/10 or worse and always has a premade with him with the same score that, guess what, is breaking his fingers to type in chat about the fact that he is the best player in the world. Seriously, I cant get out of plat because if someone dies 1 time the entire team think that the game its lost and should ff at 15. What can you do if you get players like this in your team and how do you avoid them. Dont tell me to mute them or things like this because that wont change anything in terms of gameplay and In some cases if you dont give them attention they go afk or int.