Just report it directly to the Education Bureau. Under normal circumstances, the education bureau takes the form that people do not sue officials and do not investigate. It is a popular trend for teachers to run remedial classes. As long as someone reports it, he will definitely visit, but if he wants to report it, he will definitely leave your phone number and name. If this teacher has a background, he will surely find that your children go to school with him. Is this good for the children?