ELO Hell Getting rigged by riot

I can be winning or drawing in my lane, by 8 min all I hear is enemy killing spree, enemy rampage. It's freaking ridiculous and it's happening more than 50%. I cleared my promotion had 4 feeder games in a row, then won 2 and lost 3 and demoted. How do you carry out of this? It's practially impossible. I feel like i'm wasting my time playing this game and its like a drawn out game of poker with no monetary reward.