Send text messages to insult and slander me maliciously, and send text messages to everyone in the unit in groups.

This is a civil tort. The police station can only warn you and does not support your compensation. If you want compensation, go to court yourself.

The result is probably that he sent another short message to the whole company, telling the whole company that XX was slandering the other day, I was wrong, and so on. You can ask for a public apology.

You will get symbolic compensation. Maybe only 10 yuan. Because you are not a celebrity, your reputation is worthless.