The first thing that you should do to stop someone from harassing you is to give a clear signal to them that you have no intention of letting them continue their behaviour.
In most cases, the victim becomes scared when subjected to harassment and consequently ends up becoming even more vulnerable. However, a person who clearly shows a clear intent to defend him/herself, instead of breaking down or getting scared makes the harasser think twice before continuing his/her annoying and offensive behaviour.
Another effective way to bring harassment to an end is to break all contact with the harasser. The latter will feel encouraged to continue behaving offensively as long as they are getting a response and reaction from you, even if it is an angry outburst or a long string of profanities.
You can however make them stop by showing absolutely no reaction to whatever it is that they are saying or doing. This, of course, only applies to psychological harassment, as you cannot possibly ignore the harasser in case of physical or sexual harassment.
If the harassment is of a physical or sexual nature, the best thing to do is to get help from a powerful authority. If you are getting harassed in office, notify your boss. In case you are getting harassed in school, notify your teacher or principal. In case you are getting harassed outside of office or school, get the police involved.
Keep yourself safe from the harasser by taking certain security measures such as securing your home properly, blocking the harasser’s phone number, hiring a guard for a few days and removing your personal information from the Internet. Once you do all these things, you will immediately begin to feel safer and calmer.
Confront the harasser if you think you are up to it. If you are a male, threaten to send them to the ICU if they do not stop harassing you. If you are a female, threaten to get them beaten up by your boyfriend, husband or brothers. Make the threat sound as genuine as possible. Just do not say something that can possibly get you in trouble with the law later on, such as “I will kill you.”