The problem with the match making system right now

My holidays started about 70 days back and I was really excited to play Ranked duo with my friend since the beginning. Initially it was going good, then after the latest patch we've lost about 30 games out of 35 games. Always what happens is there is either a troller or giving up person in our team, always. This never happened before. Because of this, we even stopped playing LoL now. I love this game and I hope this match making will get fixed.