Afk's are out of control, when will riot fix it?

I've had multiple ranked games where someone afk's within the first few minutes of the game and I end up losing because its 4v5. (by AFK I mean sitting in base or just running around doing nothing, or even leaving the game entirely.) Riot doesn't seem to care about it and people on the opposing team say they wont report the afk'er, obviously because they are winning. If someone rage quits and makes the team lose their game, with enough reports, shouldn't riot have a forgiveness program or the like? Losing a bunch of games and losing all the LP I've been working hard for and grinding for is starting to really suck.

My previous game, I had a person get mad that he got autofilled support and not adc, so he went yasuo support and intentionally fed the entire game. No he was not doing bad, he literally walked into the enemy team and would die on purpose. Then I had a teemo ragequit because he died twice within the first 5 minutes. Yesterday, I had 3 games in a row with a person whose name I know by heart now because they fed the enemy team each game and was being a complete troll. Sure, maybe they had an off day, but if the are in my queue, then I have to deal with it because if I dodge I lose LP anyway and also get a queue limit.

It is completely unfair that people are able to ruin your game and your rank that you've been working so hard to get up. Why won't Riot do anything about it?