You can always call the police if you feel endangered or threatened. The FCC (US) has a place you can also file a complaint if they are sales related calls or collection groups that are, again, threatening or harassing in nature. https://www.fcc.gov/ Your cell provider should have instructions or your phone manual, with a list of things like how to block a call. Without knowing what your phone is, or your carrier, a quick google search should get you accurate information.