i am in trouble please help

[Leon]

and if I may summarize what I understand from all the answers is that there is no way that the visa that has been issued to him be revoked

You can not force his visa to be revoked but you should still let immigration know that you believe now that he only married you to be included on your PR application and that you are divorcing him.

You are also obligated to let them know if your family composition changes before landing so you should let immigration know that you are divorcing him because that may be of interest to them, even if they may not cancel his visa because of it