2018 ranked season

So hear me out, I'm amazed how this rank match making works. So I did my placements, aight, I did my games, raised up my rank with 3-4 divisions in like two days but then it started happening as every season so far. I'm getting placed with people who are 2-3 divisions lower than me with in the best case scenario with 30% win rates while the team AGAINST me are with over 4 divisions higher and over 50% winrates. This happened in over 10 games so far and it's honestly just making me wan't to quit like a ton of other people. How exactly does this matchmaking work cause this seems like a joke at this point, in 5-6 of my games I had people who said that they WILL troll (right in champ select) and they actually did while the enemy team has normal people? Oh and don't tell me it's because of my account or anything cause I started playing with a friend and this continues to happen, to me, to him and even when we play together lol. [sg-ahri-1] This just feels like a joke and as if Riot are having fun doing this at this point.