It seems to me that the reason for faults issues taking longer to escalate is not PN but BT.
In this weeks Uxbridge Gazette is an open letter from a BT engineer. He wrote in because a cabinet in South Ruislip was hit by a car and it took over 6 weeks to get it fixed during which time affected houses had no internet.
He writes that BT have reduced the number of qualified engineers. He goes on to say that the offshore call centre does not understand local issues. He writes that the South Ruislip cabinet would have been fixed within a week with overtime or shift work. I assume from this that both are now non existent so the engineers are 9 to 5 and fewer of them.
His parting statement is that BT are now far more interested in selling their products than looking after existing customers.
Let's be careful out there !