Even if you move her, I think you need to talk to the teachers, and also the people who cast as they may very well be different, and see what they can tell you about why she isn't being cast (in a very non-confrontational manner, no matter how angry you are- it should be more of a "what do we need to work on to give her a better chance at being cast"). How many kids are in the school as opposed to how many are in the productions? Is there something they think she specifically needs to work on? Can she not remember her lines? Does she freeze up at auditions? Is it strictly acting, or is it a musical- in which case does she have issues with her singing or dancing? Does she not get cast because the decision makers feel that others are better at acting, or are better fits for the roles, or is there something else such as her attitude or the way she interacts with other students or teachers. If it is a talent thing, is it something they feel she can work on, or is drama just not going to be a good area for her (think of the American Idol auditions- sometimes no matter how much you want something to be "your thing", it just isn't). Even if they don't think she has the talent, if it is something she really wants, I wouldn't give up completely although I would change her schools and see what her other teachers say. Even if she isn't a "natural", if it is what she really wants to do, with hard work she might be able to improve a lot.
They will keep taking your money whether they cast her or not. One, because they want to fill the class. Two, because the idea is that she should be learning in the class and hopefully improving to maybe get a role the next time Three, because the classes are usually treated as totally separate things than the productions. It is never assumed that everyone in a class will try out or get a role in the productions.
You would be in the same boat in the better drama schools around here. If it is a "professional" type drama school or connected to a local theater (non-kid), it doesn't matter how much you pay them or how many years your kid has been there, if the other kids are better, then they are going to get all the roles and your kid isn't. Drama and theater are very competitive around here. It doesn't matter how many years or how much money you spend, the roles are going to go to the kids they think will be the best in the roles and the play. There also can be some "politics" in it- local actors kids, donor's kids, etc. might get some preferential treatment. Also, depending on her age, one year is nothing- around here the kids start young- I'm talking age 3 or 4 even though they are not eligible for productions until they are somewhere between 6 and 8 depending on the school-, and if the talent is equal, the kids who have been there longer will get a role over a newcomer- in fact sometimes the plays are even picked with an idea of who they are likely going to put in the role (however, a new super talent can show up and suddenly blow everyone else out of the water). Plus the schools are competitive with each other, and they want their productions to be as good as possible. They won't put kids in them just to have them there.
I'm sorry for your daughter. It stinks when the cast list is put up, and your name isn't on it, especially if it happens more than once. Unfortunately, that is part of drama and you have to have really tough skin if you want to focus in that area.
My daughter has been taking drama classes 2 hours per week for the past year (to the tune of $875 we've given them - I just added it up). She has auditioned for every play they've offered and never been given a part. At first I chalked it up to every kid needs to learn that it's hard work and sometimes disappointing. But she is now on her 2nd year of study with this organization (which bills itself as Christian 
) and the cast list just came in and she doesn't even get a background part with no lines? I understand some kids might be a natural but come on - at least reward her hard work this year and stick-to-it-iveness.
That's what my mandolin teacher told me about 30 years ago, LOL. I was so horrible that he kept giving me lessons, but stopped charging me for them. I finally put the mandolin behind the sofa and put us both out of our misery.
