Why is it IMPOSSIBLE to win series games? I've lost 4/4 promo series since S7 started.

Each game I get LITERALLY incompetent players in my team. IMPOSSIBLE to win. I would fail my series, jump back on a win streak or similar, then hit the series again. I lose every game even if I win lane, I know exactly what to do. But with my teammates that I get..... They run around like monkeys doing the dumbest shit. I think most of them actually try to lose. What is wrong with your matchmaking system riot? Yuo changed it didnt you? Yuo made it literally impossible to climb now. I've won ONE GAME. ONE GAME in 4 PROMO SERIES. And yuo know who my teammates were? They fucking said they were master smurfs or some shit. And we BARELY won.

And last game honestly my enemies were so good. It almost felt like they were scripting. Lmao. And my teammates were trolling. My kalista had frozen mallet. My thresh is just trying to have fun. My twisted fate gold cards Tank J4 instead of Jayce claiming J4 is the strongest member. My Frozen mallet kalista and thresh are focusing Jarvan instead of Jayce.