In the event that a gift is redeemed and the card charge fails, an error banner will appear at the top of the account for all users.
This error banner will include a call-to-action for Admins to edit the payment method or retry the card. This will take you to the Team Settings page where the card can be updated or to the Gift History page where you can retry the card for the specific purchase that failed.
In Gift History, you will also notice the failed payment is reflected, and you can retry the payment here as well:
Please note: If the failed payment goes unresolved, &Open reserves the right to cancel the transaction.