What should I do if I am targeted by mental patients at work and harassed by phone messages?

First, put the number on the blacklist. If there is any abnormal performance or affects their normal life, they can be warned by the public security organs and persuaded to restrain their families. If this method can't get effective results, you can only be responsible for any impact on your life through court channels. You can also find his weakness and fear it, as long as you can't break the law.