11/6/5 Cho'Gath demoted because afk

You most likely have actually won games because the other team has an AFK player. In fact, as long as you don't AFK, the other team is more likely to have one than you.

People just tend to remember when AFK players are on their team but either don't remember or don't complain when they are on the other team.

hehe xd

It happens. Just wait till you get onto a team that has 2 afks lol.

You wouldn't have been demoted if your stats, your mmr, your win rate weren't already far, far below your division.