My DD's school is worried about enrollment numbers dropping dramatically. Apparently the 2-3 kids headed to the gifted magnet in the fall pushes the numbers over the edge enough that they have to drop a teacher for 4th grade. One of the teachers there (who happens to have been my DS's teacher and we pulled him out mid-year) approached one of these gifted magnet school moms and said something along the lines of "Your child is so HAPPY here. You know, she doesn't need to be pushed, she is doing just fine here." My response would have been "Maybe if you guys actually gave my children work that was the correct level I wouldn't feel the need to pursue something like a Gifted magnet program." But of course, what you actually say and what you should say end up usually being two different things.
DS's new teacher at a different school seems to truly understand the issue and has gone to extreme measures to try to figure him out. She actually asked the principal for time off so she could test him and has a huge binder with all kinds of test results and papers on DS. But that has not been our overall experience with the others. Everything is a fight. By simply asking for my child to be assessed at a higher level, I was labeled as a pushy tiger mom. I feel like some of these teachers are jealous or feel threatened, just like other parents in the general population would be if you started discussing your child's IQs. Most of them have kids themselves and those kids are NOT gifted. Just because teachers supposedly want kids to learn, doesn't mean they feel any less threatened by kids who are very advanced.
It's also true that elem. teachers in general don't seem to be very deep thinkers (to put it kindly) and that extends to elementary administration as well. Both of my kids have special needs and whenever (with a couple exceptions) I have attempted to broach that subject in an effort to figure out what's going on, their eyes glaze over. They don't know what you're talking about, aren't particularly interested, and they make no effort to do research or figure it out, either. I occasionally send a link, for instance explaining a particular disability like dysgraphia, and I don't know if they bother to even open things like that up. In the school I tutored in last year, there were a few kids I had concerns about and talking to their classroom teachers about it and getting them to actually do something about it was like beating my head on a brick wall.

Sorry that went off on a tangent. Hang in there and keep advocating. Hopefully a light bulb will turn on with someone there.