Asda Petrol double charging

Well here is an interesting thing. I looked at my on-line banking today and saw I had been charged twice (same merchant, same amount, different dates one day apart) on my debit card for a transaction. I called my bank to question this, ‘cos I certainly didn’t fill my car up twice… As soon as the lady heard me say “Asda Petrol” as the merchant, she stopped me. It would seem, according to my bank, that Asda have double charged a whole lot of people due to a “major processing error” on their end. I should be refunded by “the middle of next week”. One wonders how wide a scale this double charging is. I have heard nothing on the news and there is nothing on the internet, yet my bank knew right away of the issue when I said “Asda Petrol”. I hate to think what would have happened if I had not had a spare 40quid in my account – I’d certainly be asking Asda to pay charges. How can this happen in a modern banking world? Still, for me, no harm done and I’ll be happy once I am refunded. I will think twice though before using Asda’s pay-at-pump again though.