You aren't doing enough about the feeders

Me and my friend were on a winning streak. 4 wins in a row on ranked. Then along came a troll. we noticed him immediately in the lobby. he even admitted to being a troll. we didn't want to dodge because my friend was in his promos. we thought we could at least give it a shot. the troll went alistar support. the moment our adc dies is the moment the trolling began. this guy decides that he "refuses to lane with a bad adc" so he goes in top lane with my friend. feeds enemy pantheon. then he goes mid with me. feeds enemy Twisted fate. meanwhile our bot lane is 2v1 and losing. you arent doing enough about these feeders. perma ban them. i cant believe people like this are even allowed to play the game. i'm incredibly disappointed. makes me not want to play anymore.