Back in the 70s worked at a place which still had a very old telephone exchange where the operator plugged cables in to connect 'phones to the outside world. Internal calls could be dialled.
Whenever we tried on our shared office phone to get an outside call, the operator never answered us. The managers in the offices on either side had no problem. One day a colleague got fed up and used a manager's phone to ask the operator why we were ignored.
The response was "Oh! Your bulb has blown so your line never lit up. I'll change it"
We never had any further trouble - until a modern exchange was installed!