Prank phone calls are intrusive and troublesome. Not knowing who the person on the other line is, or what number he is calling from stops you from taking action. Often times the only way a telephone company will work to remedy these situations is if you file a formal complaint with the police.
Write down as much information about the prank call as possible. Note the gender of the caller, the tone of voice, the approximate age and any background noises you hear.
Call your local police department on its non-emergency number. Let them know you will need to file a formal complaint against a harassing caller. There is no need to physically go to the police department, as making the call is sufficient. A report will be taken over the phone. You can find the non-emergency phone number in your local phone book.
File a report every time you receive a prank call. You want to ensure that the telephone company has an accurate account of the time, and amount of times you are receiving the calls.