06-07-2022 08:05 PM
06-07-2022 10:11 PM - edited 06-07-2022 10:12 PM
Have you tried registering the card details under My48 Account > My Profile > Payment Details on your account rather than entering them on demand assuming that you're doing the latter?
If you have the same problem in both places then you'll have to contact 48 support.
See the link in my signature below or email them at support@48months.zendesk.com
I think this happens when the card verification (e.g. 3D Secure, Verified by VISA etc.) can't complete for some reason even if the card has been used online for other transactions.