Calico, just recreate in text all of the wording on the card here. Particularly the phone number. Don't give us the numbers, though, and I'm sure we'll be able to figure out if it's genuine or not.
Probably a scam, and the number is also probably an uber-high-rate phone number. But maybe British Telecom will be able to tell me if it is.
But also do a Google search on a specific length of text "in quotes" first.