I was interviewed for the teacher recruitment exam, and my previous school sealed my diploma. The school said that if you leave halfway, you won't return your diploma, so you can't go to the qualification examination.
I suggest you consult the Education Bureau. There must be something wrong with the school's practice. What do you mean, leave halfway? It means that you left halfway when you dropped out of school or issued your diploma. If it is the latter, then it is wrong for the school to do so. If you drop out of school, it makes sense not to send it.
However, you can apply to the school for a replacement.
Teacher Shen of Hongbo Kindergarten answered.