Twisted Tree Line Feeders

So I have played a few games in Twisted Treeline the 3v3 game . At first I was playing with a friend and another guy , the game went great we all communicated well but the other team seemed odd. Then I started playing them on my own , games seemed way to easy as I am not a huge rank player , so it seemed odd I was getting as many kills as I was. Then when trying to talk to my team no on responded they waited , got killed on purpose, the other team would run away. WHY IN THE HELL IS RIOT ALLOWING FEEDERS IN !!! I know it isnt a ranked game and all but it isnt fun and I play when Im short on time or just dont feel like playing normal. Yeah you could say stop complaining your getting tons of kills and farming , but it just isnt fun when you play against people who will run away or just stand there or you to kill them. Just my thought.