Players so blatantly trolling yet not getting bans..

I don't understand how a player can literally admit to intentional feeding yet they do not get banned.... honestly I'm beginning to consider quitting playing because of the weight that each player carries in a game and how I am basically sitting at a middle school lunch table every time I play a game of league. I don't even know how to describe how disappointed it makes me when I lose to a team that's been fed by my own team mate.

The one thing I can't get past is the fact that I know I'm a better player than what I'm ranked, yet I can't hyper carry every game to rank up, and I continuously lose LP when I'm paired with a team who, for instance, picks ADC champs for every lane, or a team that gives up after losing first blood. So I'm good enough to play with a team and properly play my role, but I'm not good enough to 1v5 an entire team. Trying not to make this look like a bitchy post so please if anyone has a solution to my problem please share....