Is Riot doing their job punishing feeders, griefers, and intentional afkers?

As a player who played this game since the introduction of Shyvana back in 2011 I am very disappointed at Riot for their lack of ability to punish players who feed or afk on purpose. About 8 months ago I was matched with a player and he has proceeded to feed on purpose as a Lee Sin with a 0 kill and 10 deaths in my game and found out that he has been consistently feeding his enemy team for almost 20 straight games over the span of 3 days and Riot what so ever did not take action until I submitted a ticket. They claim that reporting a player through the client after the game works I feel that is not true at all what so ever. I am sure any player would have reported that Lee Sin and now the Fizz I was recently matched with yet they are still able to play unpunished.

This Fizz has since the beginning threatened the team to afk if his teammates feed, he proceeded to afk after 8 minutes when the game was still winnable he has done that in his past 3 games making his team to lose and he was still able to play after I posted a ticket. This is unacceptable by Riot and also shouldn't Riot be more transparent and inform certain players like Fizz or Lee Sin is punished or not? This is not fair for honest players who tries their best and work hard to win games, I have had many accounts that were banned for toxicity it seems Riot is taking focus on things that are unnecessary. Afk, griefing, and feeding are worse actions compared to being toxic and I feel Riot does nothing at punishing players who engage in these 3 things at all because they allow players to afk, grief and feed for 3 to 20 games straight.