Contact VISA security - the number's on the back of the card, that's if it is a VISA card. In any case contact the security department of the card company. They work 24/7 every day of the year.

It happened to me, and I discovered that someone had tried to use my card to buy a load of expensive clothes in Mumbai, except it wasn't my card; that had been cloned in a petrol station in North London.

The VISA transaction software spotted that I had used the card in London six hours earlier, and had worked out that I couldn't possibly have been in Mumbai at the time of the attempted transaction. It stopped both the transaction and the card, all automatically.

The same thing might have happened in your case. I hope not, but you can rapidly find out by calling them.

"three different cards, on three different banks made me think it was more general than specific to me."

The fact that your cards were refused on two separate transactions does point towards a specific problem with the cards, although it would seem unlikely that someone has cloned three different cards at the same time.

The card providers will soon tell you what the problem was.

With the technology used nowadays, I would suspect that it was a 'issue' in the system.

I had a problem in Asda a couple of weeks ago, when for some reason their system refused to 'authorise' a 'Mastercard' credit card on two attempts, but on the third , the transaction went straight through. That morning I had used the card at other outlets without any problems. And it wasn't a case of fund shortages at Asda.

The Asda checkout person, did say that this 'happens' from time to time. It just seemed a normal days experience to her!.

Would perhaps add, that when I tried to paid the DVLA, their on-line system refused credit card payments, and making telephone contact, the advisor cleared the transaction, using the same credit card information, with no problems. Again, it was suggested that this was an issue with the system, and one which the advisor was well aware about!.