When Teammates obviously troll/feed but riots system doesn't ban them

I was just putting out there that this mostly occurs at low level of play, but many players intentionally troll or feed in silver or below. It gets to a point where it is so frustrating to play with when you feel you are going to automatically loose half of your games because of one player. Now this itself is going to happen but the biggest problem is these players are not even getting punished. My past 5 ranked games, 4 of them i had either a troll, or an AFK in base and couldn't do anything about it. However, i just went to check t see if any of them got banned but they are all still recently playing games. If riot allows this in ranked then how can lower level players ever expect to climb at any sort of decent rate. I feel this should be a bigger issue but riot usually doesn't listen to lower elo players other then when they are skin concepts or champion ideas due to them not trusting us in a game play standpoint. I understand we don't understand the game to a degree of a diamond player, but when i can't even report my teammate for going 0/6 because when you know they are trolling, but they just say "sorry i am bad" and riot says that is ok, how can u expect any players to want to play ranked or try and climb. Is report for unskilled player coming back or is there something else we can do? anyone else have thoughts? thank you for all who reply, do not be afraid if you are a low elo player, we have a voice too! we make up the majority of league players!