We were hoping it wouldn't come to this

Our kids at GOTR continue to be disrespectful to the coaches, mean to each other, and just don't listen. We (the other coaches and I) kept trying to tell ourselves that it was just the age range, but lately the rudeness seems to have gotten so much worse. So it's time to have a come to Jesus talk with them, and unfortunately start doling out some consequences for failure to listen and show respect. Crazily enough, that's one of the premises of GOTR. To listen to each member and show respect for themselves as well as each other.
I think the problem is that we are too nice to these kids. There are really only two or three instigators, so maybe this is a case of cut off the dragon's head and the rest will fall into line? I'm certainly hoping so. So far we've talked about making kids who don't show respect or are mean to other members sit out of some of the fun stuff or maybe lose their snack at the end of practice. I'm not really sure how well either of these will work out. We're not to the point yet where we need to physically remove kids from the practices, but I could see it getting to that point fairly quickly.
The biggest problem at this point is that we send home emails telling the parents how we've had problems with lack of respect and that the parents need to discuss with their daughters how important it is to listen and be nice to each other...but the parents either don't want to believe that their daughter is part of the problem or don't fully understand the magnitude of the problem. Either way, something has to give...I so don't want to be the pissed off angry coach who has to yell to get her point across.