I'm stuck at Silver V since I am losing a lot of games recently. that's why I play most of the time around dawn just to be sure there aren't any kids around playing. But there are still times when 4 of my team mates are kids who test champs on ranked games which is really frustrating. I mean they can always do that on normal games or try using the practice tool.

Even though i understand how you feel, you need to realize that it depends mostly on you to carry your team and to perform well, even though having toxic and immature teammates can affect you, you should try not to let it make you lose focus and just concentrate on your game.