Forever plat 3

So after sometime of not playing ranked(because i failed promos to plat 2) i decide to get to plat 2. Today after winning a game and getting promos i was very happy. The first game went pretty well and we won. The second game went really went, we had a fed kha'zix on our team it looked liked we would win, SUDDENLY kha'zix decides to throw the match. I took a break and after 2 hours i decided to play again. And i got janna support with grasp. I thought we were %%%%ed but our botlane managed to get 4 kills so kaisa was 4-0-0. SUDDENLY kaisa keeps on dying and ends up with 8/10. Our midlaner is also doing very good and keeps on dying. Our jungler(shaco) doesn't give a %%%% about his team and keeps on farming and going for 1v5 assassinations. As for me i was on top as darius and i was trashing garen. BTW we lost and i failed my promos once again. RITO PLS FIX MY TEAM Also in the last game the enemy team was almost full ad however noone(except me) bought ninja tabis.