In general, in fact, you can directly ask the occupied teacher not to occupy music and physical education class, but to attend the self-study class instead. Or tell the music and physical education teacher not to allow other teachers to take his classes ...
In my previous school, it was strictly forbidden for the teacher who took the main class to occupy the main class in the sub-class ... If you must, you must apply to the principal and use it in the evening or afternoon self-study class! ! !
When complaining, it's best for two or more people to go to the teacher together and say that if one person is alone, the teacher will ignore it. (I thought you were making trouble)