Not been called on for 4 years.
They don't know I am here and don't bother with the area I live in at all.
I would imagine Do Not Calls are often people with more knowledge about jwdom than the average householder and so are prepared to make a stand against them.
The ones who know nothing have a moan but are not pro-active to stop the intrusion.
Would the bOrg want unsuspecting publishers calling on houses where the occupier might know more about watchtower history than the person selling the religion?
Control, always.