Customer payment declined

This is normally an issue more often than not on the customer side as they
managed to reach the payment gateway to transact. On a rare occasion there
may be an issue on the Bankserv side.

Solution:

Is the bank card supported by the payment gateway? Visa or Mastercard?
Example Tyme Bank is not currently supported.

Another issue is that customers normally get the OTP wrong or don't receive the message at all from the bank on their side.

This will also cause an Authentication decline error.
A recent issue is with FNB. Authorization is required on the app and sometimes they don't receive authorization to do so which results in a transaction declined. Best practice to login to app and keep app open when making payments.
The payment gateway environment is separate from our actual website.