Here is some support information and you can find our contacts below as well
Before you add card be sure that you have internet payments enabled with your bank card issuer. For additional security please check also, is your date and time correct in your smartphone. If you add card then system displays error message, be sure that if you contact with the support you can describe exactly the error message.
If you can not pay you might face following issues:
Every merchant has the sortcode, which is displayed near the point of sale or other places where payment is initiated usually. You must enter the shortcode in the search field in the payment section of your wallet. Easier way is to scan QR code or tap the NFC.
If you are a iPhone user then you should use QR as Apple does not support NFC for older models of iPhone. If you are Android user then make sure that your phone supports NFC and it is enabled as well.
You can delete bank card by long press on a bank card number. Then according dialog window will occur
Be sure that you have entered "next" button. Merchant shortcode on the blue background and alert about the payment in progress will be the indicator of started payment session.