potential punishment changes in ranked ?!

I just had to speak about this because this is getting so frustrating in this server.. being stuck in silver because a member or two of your team rage quit or just go AFK for no reason. i played a matched where a riven played lost 1/2 of his hp to yasuo he just said "BYE!!" and quit and i lost 15 LP because of a player like that. By what means i lose LP because a player got auto fill and picks yi support or any non support champion and go troll because " i was auto fill support f*** you all " How is it fair that when you dodge a queue where a players wants another lane because he didn't get it and the other guy refuses so he says "TOP OR FEED" And a lot of them do feed or troll I'm stuck in Silver because i win a match and lose two because of either AFK, Troll, Punishments should change Something has to be done because this is getting on my nerves!