This guy calls every single day about a mortgage company. He says his name is David and once I say take my number off he hangs up. Then calls back the next day . I answer and he says he is a different name and I told him I will report him for harassment.
It's a spoofed number. Spammers set up their caller ID to display invalid numbers to make them harder to track down. The simple solution is to NEVER answer a call from obvious invalid numbers such as xxx-000-0000.