......Customers must phone a call centre if their card is declined
Banks are refusing to help customers unblock credit cards in branches. Anyone whose card is unexpectedly declined while shopping must now phone the bank's call centre instead. Lloyds, Santander, Nationwide, NatWest, Virgin Money, HSBC and Barclaycard all confirmed staff cannot unblock credit cards in branch. HSBC, Nationwide, Lloyds and Santander, said they could not deal with blocked debit cards either.
Source: This is Money