I ref & I coach.
IMO most coaches and spectators are too harsh on refs; most refs are genuinely doing their best and do a reasonable job given how hard the task can be at times. Before I started reffing I used to comment on every mistake the refs made, now I make myself put up with 10 errors before I am allowed to say something and by then it's almost game over. The best quote I think I've ever heard from a rep coach about reffing:
"My players make too many mistakes for me to even START worrying about the refs!"
Top bloke, obviously. If a game is genuinely out of hand you have a few options:
1. Pull your own players into line
2. Agree with the other coach that something needs to be done and either a) call a time out and speak to your own kids, or do it as a group, or b) call a time-out and speak to the refs TOGETHER - this sends a really strong message
3. Speak to the refs, but in a friendly manner. You will get the best response if you say something like "It's getting a little rough out there and I would happy for you to call the game tighter: both ways." You might even have to cop a couple of bad calls on your guys in order to get the outcome you want, but be supportive while they're trying to get the game under control.
Biased refs? We all know they exist and they wouldn't exist if the ref coordinators had the luxury of taking them off the roster, but no matter where you play, your association is short of refs and needs more. I do the roster at my local country association and I would love to give a couple of kids the boot but without people to replace them, I can't - and these kids know it!
I copped some biased refs at a tournament recently, all the fouls were on my team, most of them dodgy. I called a time-out and spoke to the refs "I have no problem with the calls you're making on my guys [not true, but anyway] but can you please keep an eye out for the pushes we're copping under the basket?" - problem solved!
There's never a need to get nasty as a coach, and if you are more patient and tolerant you will enjoy the game more. Try it - by changing the way you think about a problem, you resolve the majority of the issue, and if you are courteous and friendly when you speak with (not "to") the refs it makes a difference.