Seriously Riot demote me for a game in which we had an afk all game and i went 0/2?????

Politely, its not just that game. The fact you had been at low lp and lost the grace period protection from demotion matter more then a single game with the afker. Relax, you sound pissed, take a break and get back at it later.

feeder

You lost a ranked game, it doesn't matter why. Get over it.

I don't know why you're getting hate. I think the ranked system sucks as well. You get dropped after ONE match with 0 LP, yet you need to win a couple matches PLUS a promos to get back to were you dropped from. Also the fact that you get these losing streaks that have factors WAY out of your control is beyond ridiculous. Placing auto filled people on your team, people who flame all match, etc. Gets old.