Use the phone system to your advantage.
Step 1 - down load the audio/tone for not in service tone (https://www.youtube.com/watch?v=NI_wyiY4vyk)
Step 2 - shorten the tone to just the tone and not the message
Step 3 - On your voice mail recording, start the recording, play the tone and wait one or two seconds, then proceed with your normal greeting.
Step 4 - Let all calls ESPECIALLY unrecognized calls, go to voice mail/messaging
Why this works. The tone is a standard telephone tone that tells auto dailers that the line is not in servcie. The vast majority of auto dialers will then take the line out of their list and not call it again.
Also helps to list your phone with the do not call registry. After about a week, you should see a significant drop in call attempts.
I dig it and that is true.
Give them a referral tone and it’s done...
I am going to download an .mp4 and see what happens.