I used to work for BT faults and we all heard 'that' call a few times! I got people, not that bad, but quite swearish a couple of times a week.
To be honest you just have to take it in your stride and think well if people get sooooo mad that their phones are out of order then there must be something wrong with them.
But that guy got his service revoked, which happens very rarely at BT, and as a result will find it very hard to get telephony service from and major provider.