FNB Credit Card system failure

FNB has automatically debited my month end credit card balance on due payment date for some years. It failed to do so on 19.12.2020 (date of due payment). A small debit (R906) was raised by FNB on 15.12.2020. I queried why the automatic debit process had failed with the bank who advised me to email my question to '***' which I did on 22.12.2020. Having had no response, I paid the full outstanding amount (R16668.90) on 23.12.2020. To date I have received no reply from FNB as of 30.12.2020. To add injury to insult, FNB added an interest charge of R417.52 to my card statement received on 28.12.2020. Questions (a) will the automatic debit process reappear on next due date (Jan 2021) or should I to an EFT from my Standard Bank account? How long should I wait for the process to activate? If I do an EFT and the automatic debit also appears, how long will it take me to get the EFT sum back? If at all?