Disconnects and first time players in my Promos

I know no one will probably ever read this, but I was frustrated enough I had to post something. Got to my Promo series and first game went well. Everyone tried and resulted in a win. Second game, zed mid gets mad at something, says DC and leaves. Second game results in a loss. Final Promo our jungler was a Riven who played her first ever Riven game in my Promos of course.

I know many people have similar stories but not ranking up because of a DC or a feeding troll who plays a champion for the first time ever in ranked feels pretty crappy. I wish Riot would address at least one of these issues, it;s not the first time i have failed these promos for similar reason. Thanks to anyone who actually read this.