Reading a number of times on here that if a child says something about their teacher or other children MN automatically say that child is lying.
When my children were young if they said something that I was uncomfortable thinking about I went and SPOKE to the teacher. Not email. And not to acuse but to discuss. If your child is upset there is always a reason that you and the teacher
Can hopefully sort out.
If you don't believe your child or get 2 sides of the story they will not tell you anything again.