Unfortunately, this happens quite often. Typically, "payment declined" means that the payment system rejected the transaction, but the bank may still temporarily hold the amount as pending. This isn't a true charge—the money is usually automatically refunded within a few hours or up to a few business days.
If there are no gift card codes and the email hasn't arrived, I would do the following:
Check whether the payment has been debited—it will be listed as a completed transaction on your statement, not as pending.
Contact the store's support team and attach a screenshot of the statement.
Wait 12-24 hours—sometimes the system simply delays issuing codes.
By the way, situations like this often arise due to unstable payment processing at the merchant. In my business, I try to use more reliable systems, like
Paykassma, where authorization and payment confirmation proceed smoothly, without such delays.
I hope your situation gets resolved quickly—cases like these are usually fairly easy to resolve through support.