Well, I had no need to worry about the technicians saying everything was fine and the visit would be chargeable.
They simply didn’t turn up.
But the funny thing is, when I looked at the incident report online, it stated the following: (translated of course)
“A technician came at the date and time agreed with you. He could not gain access to your home to check the proper operation of your line. If the fault persists, you can contact a client advisor to arrange a new appointment.”
I wonder where he went?