league formula

I've come up with a formula for league matchmaking. 1/3 of your games someone is afk or dc, 1/3 of your games someone trolls or rages and your team feeds too much, and 1/3 of your games you carry. I get into promos and my first two games someone is disconnected or afk on my team. I spent a decent amount of money on this game and now I am regretting it. I can deal with losing because I made mistakes or even ragers but, when the afk's and dc's are this frequent I question why I spent my money in the first place. What can i do about these problems?