Years ago I was a manager in a cable company.
One of our tricks was to intentionally disconnect entire apartment buildings, then wait for each individual resident to call.
If they were current in their bill, they were reconnected.
If not, they were not connected.
In some buildings as many as half the folks were stealing the service up until that point.
Rinse and repeat once a year, (once a quarter in really bad areas) and it was amazing how the number of paying customers improved...
One house at a time is the _hard_ way...
My motto—work smarter, not harder. :-)
(actually that was working smarter, I hope they promoted you or you got a better gig).