Hi AMS's mom - i'm sorry things are going so poorly for your DD5.
My gut reaction would be to ask for a different teacher, but first give this one a chance to explain. By that I mean have you told her everything that your daughter can do and explained that she needs more of a challenge, and that's why she's acting out. I'm guessing you've already done this by the sounds of things, but just laying it out. It kind of sounds like this teacher has pegged your DD as a trouble-maker, and it might be best to get out of that classroom if possible.
Is there a gifted coordinator or similar position at your DD's school? It might help to contact her and ask about testing. Also, she might have some suggestions for better teacher placement. If no gifted coordinator, might be time to contact the principal.
It might also help to look at your state's dept of education website and see if there's a GT person who can speak with who can tell you about the laws in your state. Some state's and/or district's require that a child be evaluated upon the parent's request. there may also be some resources on the website to answer some of your questions.
If your school does not do testing and your state does not require it, it might be worthwhile to get private testing. You can start by looking at Hoagiesgifted.org:
http://www.hoagiesgifted.org/psychologists.htm. Is there a GT parent group at the school? Maybe you could contact someone through that. Also, you'll want to see what you're fighting for before you get testing. If this school doesn't offer any acceleration in subject matter or class, or any differentiation for gifted kids, you may need to seek alternatives.
Just random thoughts from someone who doesn't yet have a kid in school yet. HTH.
