My daughter is a competitve dancer as well in hip hop and tap, and she takes jazz and ballet - all required for her level of team. She is 8. She has hated ballet for the 4 years she has taken it (two in pre-k and two in her dance troupe years). This year she loves it. The difference? New teacher! Her teacher is one of the Wizards Girls (Washington DC's NBA team) and she makes everythign fun.
Is there another teacher she can have? Is it possible for this teacher to find new ways to make ballet fun for her? I can guarantee you she is not the only miserable one.
However, know the commitment that dance is, quitting is not an option. If it is, she pays you back the money and does NOT go on vacation - no freaking way.
I would also tell her that if she can't suck it up and do the ballet without complaining there is absolutely no more dance. This shouldn't be miserable for you guys at all.
Ballet is really a great foundation for technique for the other classes and now I get why they have to take it, while I don't particularly care for it or paying for it, it is what it is. My daughter doesn't love it, but she doesn't complain this year.
You need to be frank with your daugther. No ballet means no jazz. And make her take the consequences of it. How old is she? My daughter at 8 knows the financial needs of dance and that M. never goes in without her checkbook. If your daughter doesn't know how much it costs and what you guys are doing for her, maybe you should explain it to her.