Marks & Spencer contactless card reader charged wrong account

Reader tried to pay with a Visa card, but Marks & Spencer's contactless card reader took the payment from a Mastercard in her wallet. Photograph: Bobby Yip/Reuters

I recently visited a Marks & Spencer store in Chichester, selected some goods and went to the tills to pay. I entered my Visa debit card into the reader but it was ejected before I could enter my pin. The assistant asked me to reinsert my card and enter my pin. Before I could do that, the till showed her that payment had been received. I asked what had happened. She replied that she didn't know, but as far as M&S were concerned the payment was made.

When I left the store I checked the receipt and payment had been made via another card – my Mastercard. I did not want to make the payment from this account but it was debited anyway. The receipt said the payment was contactless.

I have since been in touch with M&S asking them to credit the account that this amount was debited for and let me know how I can make a payment from the account I wished to use. I don't know how often this has happened but I find it very disturbing that M&S can take money from a card which is in my wallet and which I had no intention of using for a transaction. I have written to M&S at its most senior level asking how it intends to stop such unauthorised debiting but they have failed to address my concerns or answer my questions properly.

Are there any other M&S stores where this has happened that I should avoid entering in case my card is accidentally debited?MG, Sheffield, South Yorkshire

You appear to have fallen victim to an apparent glitch with the new technology behind the increasingly popular option of contactless payment and which surfaced in May – again with M&S – and which has had shoppers frantically checking their credit card statements for peculiar transactions under £20. What seemed to happen is that some shoppers with cards that use near field communication (NFC) technology bring them too close to the card reader, which completes the transaction. This must have happened with your Mastercard, presumably because it was close to the reader. This has been a nationwide hiccup – admittedly not affecting large numbers of customers – rather than one affecting individual stores.