[Suggestion] Really Punishing Toxic Players
In a game that is free to play, what does banning a player temporarily really do? If the banned player still wants to play your game, they can. They create smurf accounts and continue their bad behavior with new players. It forces your new players to play with them.
If you are going to take time from players, instead of banning their main account, you should take things they have achieved back. Take things they have earned with Influence Points or time-Input. It could be runes, rune pages, champions, levels, icons, or skins.
I, myself, would be quick to use the ignore feature, rather than fighting with another player, knowing that the time I have put into my account could be undone.
Banning is lazy way to say you are handling the problem.