Hi pidder,
Thanks for coming to Apple Support Communities for help today.
Let's be sure you have followed the steps here: Set up Apple Pay on Apple Watch. It's always possible you will need to contact the card issuer again.
"Add a card to Apple Watch with your iPhone
- Open the Apple Watch app on your iPhone.
- Tap My Watch, then tap Wallet & Apple Pay.
- If you have cards on your other Apple devices, or cards that you recently removed, tap Add next to a card you want to add, then enter the card’s CVV.
- For any other card, tap Add Card, then follow the onscreen instructions.
Your card issuer may require additional steps to verify your identity.
Add a card on Apple Watch
You can add Apple Account, credit, debit, and transit cards, right on Apple Watch.
- Open the Wallet app on your Apple Watch.
- Scroll to the bottom of the screen, then tap Add Card.
- Choose Apple Account, Debit or Credit Card, or Transit Card; then follow the onscreen instructions.
For more information about Apple Account, see the iPhone User Guide (link to come)."
If it still isn't working, let us know further details and any error messages.
Have a fantastic day!