Vodafone have advised as follows: We have been aware of the following mobile phone scam, which reads as follows:

There is a new kind of mobile phone scam. A missed call will show on your mobile phone. The number of 0709 020 3840! The last four numbers may vary, but the first four numbers will remain the same! If you call this number back, you will be charged ?50.00 per minute. People have complained about their phone bills, once they have realised the cost of the call, but apparently, this is completely legal. So beware, do not call back numbers beginning with 0709.

SPAM SCAMS NET MILLIONS

Unwanted text messages are making big sums of money for fraudsters, it is now known.

Last year, 7,000 people complained about receiving "spam" texts.

The number of spams has doubled since 2002 to around two billion a year.

Already, 70 firms have been fined and banned by the Government's watchdog for unscrupulous practices.

In a typical ploy, a mobile phone bleeps and its owner is informed by text that he or she has won ?5,000.

One such phone owner, after replying to a text promising just that, was presented with a ?25 phone bill.

Another scam is "missed call marketing", where anyone returning an unrecognised call is put through to a premium rate phone line charging as much as ?1.50 a minute.

The fraudsters concerned buy mobile phone numbers from brokers who deal entirely legally in long lists of numbers.

They can also bribe consumers to punch in someone else's mobile number when they call premium rate lines.

They also make them up. Computers are programmed to generate hundreds of thousands of random numbers, which are then sent out blindly.

But consumers are fighting back with the help of a complaints web site that goes under the name of Grumble Text.