Overpriced

Towards the middle of last year I ordered a BT network circuit for a new site we were commissioning at work. I won't go into detail but lets just say the order was for less than £20k.
It turned out to be a very convoluted job and the work itself took months to complete, involving the digging of roads etc. All along though we were confident in the knowledge of a bill to be less than £20k.
That was until November when this bill arrived at work for £671,606.38 !!!!
After half an hour spent nervously laughing about the fact that it must be wrong or a couple of us would be out of a job, the bill was queried with BT.
The person from BT was also surprised at the large amount but said she'd have to check it out and get back to us. She eventually called my boss back and knowing that he'd be bricking it, decided to wind him up..! She asked if he was sitting down then said it appeared the amount was indeed correct! PRICELESS, - they make and error of over £650k but still manage to keep their sense of humour.
Everything worked out fine in the end thanks to a rather substantial credit note arriving, but still thought it was a story worth sharing.
N.B. Obviously I have stripped all data from the bill apart from the amount.