-20 LP when our support finishes the game level 4?

It's disgusting that I get -20 LP when I lose a game where the game goes 40 mins and our support is level 4 because the idiot quit the game and went afk in the first 5 mins.

Then when I win I get only +18 LP.

This game is broken trash right now because of this new generation of garbage players, fix this crap please.