Is it normal for a school to do this (tl;dr at the bottom)

I remember when I was in year 4 I had the worst teacher I've ever had. She singled certain kids out, sadly this time it was me. This also happened to one of my friends, and he seemed to have gotten it worse than me. What was going on was she tried to force resilience on me by simply refusing to help me out with anything. My friend had the same thing happen to him, and apparently she actually injured him once (more on this later). Whenever someone else in the class saw that she wasn't helping me out and tried to help me, she would just tell them that I could do whatever it was by myself. By the way, I actually did have resilience issues back then, so this definitely didn't help at all. I had to say I wanted to die in order for her to actually do something (even though it was completely empty, it was the only way I discovered that she actually did anything with). After he got out of her class, I asked my friend about if she was doing anything like what happened to me. Wouldn't you know it? She got worse. I told him about my crappy method of getting help from her, and told him not to do it and he said he felt so abused that he would occasionally get back home in tears. It seems like the school actually started to notice what was happening, because he managed to switch classes about 3/4 through the year. In my case, the school did absolutely nothing. They wouldn't reply to any of the messages that were sent to them regarding her, and I went through the entire year. She also seemed to be really angry that my friend got out, because every time she spotted him, she'd give him this dirty look for no apparent reason. In my case, every time I saw her she pretended to be really happy to see me and all that, but it was clearly an act because she never behaved that way when I was in her class. I'm still confused by how the school completely dodged all the complaints about her, especially when there was so many. Their excuse for not caring at all was always "She's one of our best teachers, she's been here for years". A few times, I tried to move classes, and every single time I requested, they did nothing.

TL;DR: Is it normal for a school to do absolutely nothing about an emotionally abusive teacher?