Quite some years back at a company I was working for, we had a situation like was described here. Apparently there was a car dealer that was the same number as our private line board except for two digits that were reversed.
Our private line guy kept getting calls from very upset customers. He kept telling them that this number was not the car dealership. But a lot of them did not believe him.
Finally, he started making promises about what the car dealer would do. He would tell them things like, 'Sure, bring the car back. We'll even give you a loaner car to use while we are doing the work'. I would imagine there were some very angry customers for that dealer to handle when they arrived and there was no loaner car available. It slowed down after a while, but it never completely stopped.
I had an aunt that had the problem that her number was 256-WXYZ and there was a pediatrician's office in town for which the number was 254-WXYZ. Those parents were driving her crazy as they would call at all hours of the night when their children were sick. The phone company called the pediatrician and offered to change his number at no charge, but the doctor refused their offer. She started blowing a whistle into the phone when these people would call. But as it was almost always different parents calling, it did little good.
I don't know why she wouldn't change her number. She had only had that number for a few years.