I don't know if they do this anymore but at one time, you could request the person calling to make a note in their computer not to call you anymore and they suppose to honor your request.
A lon time ago, I worked for a bank that it's tel-marketers were told to honor this request from it's customers or potential customers.
I love it when at the end of a computer generated call they asked you, "if you do not want be called, select option three". Then you select option three and you still get calls from the same company.
What do I know? I have more hang-ups than the phone company.
