More serious consequences for AFK

Excuse me if it sounds like i'm raging. For the last 4 games, I have had a person afk all game on my team, or go afk on my team partway into the game (be it from not getting the role they want or first blood). I do not talk in chat in the games unless it is related to game strat., but my teammates were asking why these people afk. They are not scared of the 'light' punishment. I feel as though harsher punishments should be in place. What those punishments are, i do not know. I am using the assumption that most afk'ers are not scared of the bans based off the small sample i have observed.