If you need to update your card details (your bank has issued you with a new card for example) or you wish to check payments or cancel your FuturePay subscription then you can contact WorldPay by either email or by visiting the WorldPay Shopper Help pages.
Alternatively, you can contact WorldPay by calling them on:
0870 366 1233 from the UK
+44 122 325 8493 from the rest of the world
Just make sure you have your card to hand as you may be asked some security questions by the WorldPay staff.