You'd better complain when you don't want to stay. This situation is too common in today's society. My working hours are the same as yours. If he doesn't find fault with you and fines you for overtime, he will be generous. Especially in private enterprises, they are all harmony weeks. If you complain about him at work, you must leave at once. Complain and decide to fire him.

You can complain to the local labor arbitration commission. However, I usually collect some overtime evidence by myself, not to say who advocates who gives evidence/such as attendance, handover records, signed documents, etc.