
I had the same thing happen to our bank card last week, we checked the bank balance which was fine, went into DFS to pay £1000 off our furniture, only to be told our card had been refused.
Came home phoned the bank, it's 24/7 banking, they told us over the past week there had been two transactions 1 to British Airlines for £1900 and another to a concert ticket company for £2000, they had thankfully recognised this as 'unusual behaviour' on our account so wouldn't give authorisation without our concent.
It is really worrying though isn't it, our bank did say had the transactions gone through successfully they would have refunded the money and looked into it further. But in the meantime we've had to cancel our bank cards and wait for new ones. Luckily they arranged with the local post office for us to draw cash, or we would have been well and truly stuck......kids needed bus fare for school etc. Plus we don't use credit cards, so that was our only access to any funds.
Haven't a clue who or how somebody cloned our bank card, I don't use my cards online, only set up DD for paypal etc. the only place our card did disappear from view for a minute max. was McDonalds drive through when the young lad took the card to pay and had to go find the swipe machine, but took our card with him

looking back we now realise he shouldn't have done this.