Phone harassment occurs when you are constantly being threatened, annoyed, or harassed through a phone. It could be via a phone call and if you ever find yourself in a situation like this, the first thing to do is to block the caller through your phone settings.
Your decision however depends on the kind of harassment you encounter. If you are threatened or the harassment is quite disturbing and annoying or making you restless, you might want to take legal action. In this case, you can take note of the number and report it to the police to take action. For evidence, you can record some of your phone calls with the harasser or ask your service provider to provide your call logs with the number.
If this happens on social media, you can report the account to the authorities of the social platform and proceed to block the person. Again, if it involves any form of threat, you must take action to ensure your life and reputation are not at stake.