Have you contacted the Apple Pay Support team at the bank the issued the card?
When you try to add a card to Apple Wallet too many times within a certain time period the bank will lock that account. Some banks automatically release the lock after a set period of time. While other banks require a phone call. Blocks may not be something the local bank is all that familiar with and not troubleshoot the issue properly.
Apple may also temporarily lock the account, but generally it’ll reset after a period of time (24 to 48 hours). But this information is proprietary.
It’s also possible both entities have your account blocked. Weekends can also present an issue because systems may not reset like they doing during business days.
Have tried logging out of your Apple ID, force restarting your iPhone and then logging back into your account? Another possibility is Resetting your Network Settings. Both of these may require you to add back lost information. But can also be the cause of the issue.