There can be several reasons why a card payment may fail. The most common reason for failing is that your bank declines the transaction as potential fraud. Please contact your bank first to see if they have put a block on your card. Try placing the order again and if you are still having problems then please contact the Mail Order department on 0845 100 1000.
For international customers, there can sometimes be issues in recognising your zip/postal code. Please check with your bank for any issues and then contact the Mail Order department on 0845 100 100 if you are still having issues placing an order.