When it says free install, the installation of the equipment and that first outlet is usually covered by that. But when it comes to additional outlets or wanting work done a certain way, such as fishing the line through a wall, there are charges that come into play there.
Installing a modem and setting up the first PC is usually covered in the install if its free, want additional computers/laptops/tablets added, that's going to be extra if you want the technician to do it.
I work as a technician, there are many times I go out and the customer should have the initial part free and if it is not, I can get that fixed by calling dispatch. Any additional work though that is NOT on the order, or is, costs. We are given units per job. Adding more units is only done by adding other services to be installed. And that is the case most times. They don't tell the CSR they have 3 TV's, the expect those two to be free as well. And I hear it quite often when I explain the charges that they think the additional boxes are supposed to be free "that's what they told me on the phone." Never never never. There is always going to be fees, and all calls are recorded so they can go and review that conversation.
But I can tell you this, she has earned herself a do not service mark. While cable companies must provide service to people within the footprint, if something like this happens, they get blackballed.