My parents didn't go to the school district (they should have), but they did try and talk to her about other issues and got nowhere. She had a rule that no students were allowed to return to class after the bell rang. So if you forgot your lunch, your homework, your coat, you were screwed. Many kids were hungry the next day because they didn't have their lunchbox, or went home cold because they forgot their jacket.
She was horrible.
Yes, she was horrible.
Unfortunately, there are a lot of people in teaching jobs who should not be. The last time in Korea, my wife went to the first parent-teacher conference. She came back and told me we had to get our oldest daughter out of that class because the teacher did not like Korean/American children. I though sure she must be over-reacting (she can be that way sometimes). The next time, I went. I came back and told my wife we had to get out daughter out of that class. It took a while, and at least one other set of parents to make it happen, as well as a visit with the principal. Suddenly my daughter was sent to another class with a really good teacher. Suddenly the first teacher was sent for extra training. I don't know if she would have changed then but she getting close to retirement and I think she feared losing that and decided there were some things she could put on hold until she retired. Worked for us..
A couple of years later and my youngest daughter was in 2nd grade with a teacher who didn't want to have to get involved in anything. Including a boy who thought it was his inherent right to disrupt the class anytime he was so inclined. There was another student who decided my daughter would be a really good subject for bullying. When I talked to the teacher, she let me know that she was only responsible for what happened in her class room. I complained to my oldest daughter's 3rd grade teach. She got so angry it almost scared me.
She demanded to know the name and position of that teacher, what bus my daughter was on, exactly what and when things were happening. She told me in no uncertain terms that she would take care of it and not to concern myself with it any longer. I asked my daughter and she said she didn't know what if anything happened, but her bullyer was no longer a problem.
Sometimes the system works as it should. Sometimes it has to be prodded a bit. Unfortunately, as in your case, sometimes it doesn't help at all.
Oh, and neither of my daughters has become a bully due to their experiences.
OP, I don't know if this helps any with what you were looking for.