when your team won't group...

I just sat through a game we could have won in 25-30 minutes, but lost at 40 because team wouldn't group... I was pretty fed (19-4) but couldn't convince them to group with me. Their CC was too high for me to go in 3v5. We literally lost cause a cho gath who was 18-6 kept going after a teemo who was like 4-20...