Gradually all the Goodies' utility services are discontinued, including the telephone (they cannot go out to pay the bills). Then, later, when the nation is in the grip of poverty, the BBC cuts back their services by 100%, and the ending of television broadcasts means that the Goodies are cut off entirely from the outside world.
As the situation deteriorates, the Goodies' utility services are systematically dismantled, including their phone service (they cannot leave their homes to pay bills). In a later period of economic hardship, the BBC significantly scales back its operations, and with television broadcasts ceasing, the Goodies become completely disconnected from the outside world.