3 Tips to get you out quickly and painlessly-
Be kind and don't argue with them, because they enjoy arguing more than playing. Trust.
They hate grouping , figure out a way to make your team play together and you'll slowly realize that the team that groups more, wins more.
Play assassin junglers. 
.. etc
Split pushing in Bronze is basically an instant GG, assuming you know how to split push correctly. Just play someone who can 1v1 or 1v2 with ease and you're solid. A fed Yi or Yasuo are good options.
I agree with #1, but not sure about the rest.
What from I've seen, people in bronze actually group extensively in mid, failing to see any other strategy or possibility to play. The solution is actually to play some champion who can reliably split push, so either you can push to victory alone if they don't dedicate enough resources at you, or if they do, let your team to outpush their mid lane. People in bronze rarely know how to deal with a strong split pusher.
If you make them all communicate and be happy, they might group and play better .
Happy life happy game !
SPLIT push to gold v.
Honestly this WORKS,
Get a good split pusher and literally laugh. It's freakin easy mode.
