These anonymous callers are getting very persistent. What's even more maddening is they have started hanging up after one or two rings. After having asked, then demanding, them to stop calling my number I started telling them; "Your mother gave birth to an idiot" That's probably backfired on me but, Now it's just one or two rings.  I can at least glance at the display and ignore it with much less disruption. I figure their doing all the work now, so it's more their disruption now, to go to that trouble, while I'm moving on with my business.