Recently retired teacher. Record & take notes of everything; be very specific & detailed.
Good luck.
My son was getting verbally picked on in Jr. High. At the time a quiet and well behaved kid. But he also didn’t want to “rat” on the bully.
We finally convinced him to tell the teacher. She said she had thought something was going on between the bully and other kids but nobody ever did anything. So she kept her eye on the bully and “caught” him so the bully wouldn’t suspect my son had told her.
She called the parents in. Mom showed, but dad didn’t. She called the dad at work and he said something like “That’s my wife’s job, I’m busy.”
“No - your job right now is to be a father. If you aren’t here in 15 minutes your son is kicked out.” (Was an advanced program in a public school).
The teacher put the kid and parents on notice, and she also got him the help he needed with counseling, etc. He and my son ended up best friends. She was an amazing teacher. Lots of them still out there! (But sadly, plenty of lousy ones too.)