You can also just block partial numbers also using a wildcard " # " in place of a number ie Block area codes by 602#######, 602230####, or just block the whole 10 digit number- I also use the Digittone call blocker Plus:
Get a call blocker so as to save yourself the trouble of tracking all the times the scammers call you with this number in the Caller ID. And write a letter to the address you listed and ask the organization to put your number on its internal Do Not Call list.
Do you have to provide your name and address ? No.
Talk to the postmaster at your nearest post office about this problem and ask if you can use your initials and "General Delivery" to that post office's address, as the return address.