NO afk discipline whats so ever

I was playing with an afk 20 minutes in. Top lane riven. we where winning and she fed 0/7 15 minutes and team fought and died the 8th time but she was the only one who died in the team fight. left. we pushed hard and got an open nexus. 4/5 almost lost backed in time to defend. then our adc left. no reason given. was fed af. did high dmg. game ends and we report them we lost bc we cant do a 3/5 when im the only one that does high dmg the other to teamates are tanks. we lose game ends and i start another game. THERE ON MY FUCKING TEAM AGAIN. wheres the afk discipline?????????????? if someone goes afk they should get a penalty no matter WHAT. this is league if someone goes afk its an 90% lose. ive won 1 or 2 games with an afk but very rarely. Riot u need to discipline ur players more.