Do you have children like this in your class? I'm interested in elementary school. How do you react…

Do you have children like this in your class? I'm interested in elementary school. How do you react if your child, Adolf, is affected by their inadequate behavior? We have three boys who are simply terrorizing the whole class. It hasn't affected me directly yet, but today one of them hurt mine. His mother is not responding. The teacher said to come to a meeting, we'll sort it out. Mine is definitely not at fault, that's for sure. The teacher is aware of the situation and said something needs to be done about the boy. But she's powerless alone, apparently. Does she want us to write a collective complaint? I wrote to one mom who was also offended by this boy, she says she won't write anything. They are leaving this school soon anyway.