"BT disconnection" scam

There's been report of someone calling numbers claiming to be from BT (British Telecom ). They claim they are chasing unpaid bills and will "disconnect " unless credit card payment is made immediately. They're not "disconnecting " just staying on the line.
See
Edinburgh Evening News

Even if your bill is past it's due date it may be wise to contact the company direct yourself from the number on the bill, rather than making a payment from an unsolicited call.

Hello Nanny Ogg
Thank-you for posting the warning. It reminds me of a telephone scam that was brought to attention some months ago of someone claiming to be a telephone technician ringing unsuspecting people. (see below)
IMPORTANT INFORMATION

Confirmed by the telephone company and the Police

A friend received a telephone call during the week from an individual identifying himself as a telstra Service Technician who was conducting a test on the customers' telephone line.
The Technician stated that to complete the test the person should press the keypads nine, zero, hash and then hang up.

Luckily, the person grew suspicious and she refused the request.
Upon contacting the telephone company, the person was informed that by pressing the keypads nine, zero and hash, you are giving the requesting individual full access to your telephone line, which allows them to place long distance telephone calls that are charged to your home telephone account.

Further investigations have shown this scam has been originating from within the Australian prison system.
Please DO NOT press the telephone keypads nine, zero, hash for anyone who asks!
I encourage everyone to pass this message to as many others as possible....
April 2010

The 9-0-# email has been circulating for over 10 years, with several variations out there, and it's really time it is retired.

This is what snopes has to say about this particular email

http://www.snopes.com/fraud/telephone/jailcall.asp

This item is another example of a scam warning that has been continuously circulating via the Internet for the better part of a decade, thereby receiving vastly more publicity than it warrants. Although the warning has some kernel of truth to it, only a very small, specialized portion of the phone-using public is vulnerable to the scam described therein.

This scam does not affect residential or cell phone customers — it only applies to businesses, hospitals, government agencies, and other organizations that still use telephone private branch exchanges (PBXs) rather than Centrex lines to handle their calls. On certain PBX systems (i.e., ones for which pressing '9' is the signal to obtain an outside line, and there are no restrictions placed on outgoing calls), a scammer could gain access to place expensive, long-distance phone calls by tricking an employee into initiating the #-9-0 sequence. Outside of a few other settings where one might have to press '9' to obtain an outside line (such as hotels), the likely result of pressing #-9-0 will simply be a fast busy signal.

That sounds fair Dotti. I was unaware the 9,0, hash email was that old.
A friend sent the warning earlier in the year, being the first time I had heard such a thing. And when reading the post by Nanny, it reminded me of it.
Much obliged for the explanation.