This is something Verizon may not have thought of before: when you tell customers that the work will be done on a certain date, complete the work on that date. Your customers will be much happier.
Another idea: When customers call in to find out why the work hasn't been done, get it done right away not tomorrow. Apparently, Verizon employees are trained to say that the work is in progress, that it will be completed tomorrow, and that is all the information they can provide. I have heard this narrative repeatedly by Verizon employees.
It took me three weeks and conversations with over 50 Verizon employees (not an exaggeration) to get phone service established at my address. It took another week to get internet service set up. Four times technicians did not show up for scheduled appointments. Within two weeks of having my phone and internet service set up, it disappeared. I have been without phone service for several days now and keep getting told that my order is a priority and the matter will be fixed tomorrow.