Question about promos

Why can i go on winstreaks of 10+ in ranked, but when it comes to promos ill always go 0-2 almost immediately unless i have a duo?

Tried promos twice today,

ATTEMPT 1

Sona AFK at 10 minutes

Vayne AFK from 0 minutes

lost two 4v5's

ATTEMPT 2

0/6 draven, 0/6 nami, 1/5 sejuani 0/9 ryze

top lane afk

once again i went 0-2 in promos...

What the hell riot, if your going to make games i HAVE TO WIN in order to advance, at least make it so the people on my team acutaly give a fuck about winning...