Call them. I had a similar situation (but I still have the old card and brought it with me). I emailed their customer service a couple days ago, and they said:
You will need to call us in customer services 0818 903 001 for us to update your card, its not advised to send us the new card number by email for security reasons.
When I called, they said I didn't have to update since I still had my old card in possession. But you should call and tell them your situation so they can update your card info for you. Call during normal work hours (it's not a 24 hour line).