Call your local phone company to see if they have a service called "Call Intercept".. there is a monthly charge to have this service. With "Call Intercept", you can block any number in the United States. I have "Call Intercept" on my home phone thru Verizon and I am able to block 25 numbers. The person calling your number will get a recording saying "THE PERSON YOU ARE CALLING DOES NOT ACCEPT CALLS FROM THIS NUMBER, GOOD BYE." It's GREAT blocking Portfolio Recovery Associates from calling all day from different numbers. I am hoping that Verizon will extend call count from 25 to 50 numbers.