I have found a solution for most but not all of these robo scum calls. Add a "SIT tone" to your voice mail answering devise. We are all familiar with what a "SIT tone" is. Have you ever called a number and it is a disconnected number? You get that annoying three tone sound then a recorded woman telling you your have reached a number that is either disconnected or no longer in service. That three tone sound is the "SIT tone".
The computer dialing your home is programmed to listen for the SIT tone and if it encounters it to remove that number from their list. Thinking is that that number is no longer good. Google how to add a SIT tone to your greeting on your voicemail.
Unfortunately this won't work: Modern telephone systems can tell when you're playing a recording of the SIT tones and when your number is *really* not in service (the information is now carried via digital signals).
But more to the point, they wouldn't take your number off their calling list even if they *did* really believe it had been disconnected. They know the phone company will assign that number to someone else sooner or later (probably sooner, these days) and it costs the scammers nothing to keep trying until that happens.