Technicians and schedules

Two weeks ago, I placed an online order to request a phone line, explicitly specifying that the physical installation is already done (even though I don't know if it works or not, but that should be fairly easy for them to check). A few days later, the technician called me saying that he'd come today (two weeks after), anytime from 12.00 to 15.00, but that I'd call the company the same day to get a more accurate schedule.

Fine, I'll wait until the 23rd to do that call. But you know what happened, right? I called them this morning and they said that, effectively, the technician was coming today, from 12.30 onwards but they were unable to provide me any more specific information because the technicians have multiple appointments. What? Again, WHAT? At this age of technology, can't we implement a system to track technicians and their schedules? Can't we make some approximations of how long each visit will take? I bet it's trivial if you put in just some common sense.

People have jobs, and they can't leave anytime for unknown periods of time; granted, I have some more freedom at Google, but that is absolutely not the case for most other companies. If you have to be at home at 12.30 sharp, and the appointment will last 30 minutes approximately, that is one thing, but having to be at home from 12.30 for an unexpected period of time, that is a very different thing.

Just wondering... couldn't they just make the technician call you about 20-30 minutes before arrival so that you could make the same arrangements as him and be there at the same time? It doesn't seem such an insane request.