A way to leave AFK games without losing LP.

So, i just got back from my third attempt in promos to plat in 2 weeks. And in every single one of these attempts i had more then one game where someone goes AFK. I don't know if it's a cruel joke but as soon as i hit promo it turns into Trollville.

Can you please fix this? It's not fun to play a game where u are playing 4vs5 from the start, especially if its your promos.