Is your refrigerator running?

I've been getting crank or prank calls for several months now. I know what his name is, it's Charles Auburn. I know what his number is, it's 760-568-5882. What I don't understand is why he won't leave me alone. It started a few months back with him asking for someone who didn't live here but had my last name. "No, there's no Mike Smith here. No, no Wayne Smith, no Steve Smith either.....you have the wrong number." Then he called back and kept asking me if I knew all these different people with my last name. I even got out my phone book and helped him find one of them and gave him the number. Since then he and all his family keep calling back looking for yet more people so I finally said, "I don't know these people, it's not even my name, I just kept my ex's last name to piss off the new wife, ok? Leave me alone."

Well they still call me several time a day almost every day. I've had 3 calls so far this morning. They won't leave me alone. I've screamed to the top of my lungs in the phone, I've used every fowl word in the book, I've simply clicked the phone on then off again before they could say a word...nothing works. I don't want to spend the money to have their number blocked, they would just use another phone anyway.

Their not threatening me so I can't call the police. What would you do? How do you get rid of phone pests?