1. Robocalls to home phone gave me fits.
  2. Forward home phone to iPhone.
  3. Settings>Phone>Silence Unknown Callers.
  4. Change voice greeting to encourage VM from legitimate callers.
  5. Update contacts when they do.
  6. Greet phone callers cheerfully, not leerily.
My main blog is the Tipsy Teetotaler, http://intellectualoid.com.