Invalid or unsupported transaction type: The transaction attempted is not supported by the payment gateway or the card network.
Card issuer temporarily unavailable: The bank's systems may be experiencing downtime or unable to authorize the transaction at the moment.
Card issues or restrictions: The customer's card may be blocked, expired, or not authorized for the attempted transaction type (e.g., international transactions).
Advise the customer to contact their bank for clarification and to ensure their card is properly configured for the type of purchase.
Suggest using an alternative payment method if the issue persists.
Ensure that all required transaction parameters are correctly provided in the API or payment request.
If the problem continues, contact the payment gateway support team to investigate any potential configuration or compatibility issues.