IN THE FACE of plunging sales and dwindling customer confidence, Marks & Spencer has finally decided to honour credit cards. The group's seven hundred stores will start accepting Visa and Mastercard in time for the pre-Christmas spendfest. Said a company spoke: 'Credit cards are something that customers ask us about although it is not at the top of their list of requests. As we have 5.25 million storecard holders it is a big business decision to make.' The move presages a surge in direct marketing and online activity. A recent M&S promotion backfired after wily customers spotted a lucrative loophole. The chain's Autumn Windfall promo offered a free £5 voucher for every £25 spent on clothing and homeware. Customers were entitled to up to four vouchers but a number of shoppers were later discovered sidling round to the customer service desk to take advantage of M&S' no-quibble refund policy, returning the goods they had just purchased for a refund - and keeping the free vouchers! Said a spoke: 'The promotion has been very well received by our customers. If people decide to return the goods, they are asked to return the vouchers.' She then reluctantly admitted: 'We cannot force them to return the vouchers. It's not proving a problem. Most people are handing them back.'