that we've had several previous threads on this topic.
This scam was operating about a year ago - in December 2005 - but was shut down back at the beginning of this year.
In fact, the part about the £15 call charge was an urban myth - it never happened. It isn't possible for a £15 call charge to be made in this way. People who rang the number were charged at £1.50 a minute, which is bad enough.