Phone abuse is an increasing problem as technology becomes more common, greatly facilitating solicitations of all types. Also, harassing calls can occur when perpetrators think they can escape detection. When calls like these get out of control, it's important to know what you can do to protect yourself.
Register on the national "Do not call" list. Visit donotcall.gov or call the toll-free number 1-888-382-1222. The list will accept both cell and landline numbers. Once you are added, telemarketers are no longer allowed to solicit you.
Report harassment from a debt collector at ftccomplaintassistant.gov or call toll-free 1-877-382-4357. Also report the harassment to your state's attorney general, whose contact information you can find on naag.org.
Call your phone company to report further abuse, even if it comes from a private citizen, not a telemarketer or debt collector. The company can perhaps help you trace the calls or even call the offending party in an attempt to end the harassment. At a minimum, it will advise you on a further course of action.
File a complaint with your local police station. This is particularly important if the phone abuse is frightening you, or if you feel you may be in real danger. The police can work with you and your phone provider to track down the abuser and can take legal action, if necessary.