Pathetic loans department

I've been a FNB client for 10YEARS!!! I've never in my life experienced this! I paid off my loan on the 11th of November already. I sent them a proof of payment and obviously allowed the funds to reflect by waiting a few days. On the 16th of Nov they sent me an email that the amount was received and to allow them 48 hours turn around time to close the account. I once again allowed time to pass! My payday is on the 25th of November and I was getting worried that i have not had any feedback as yet about the status of my PAID UP LOAN. I called them a few times and was told that there is a delay and they will close it asap. I then called them again and expressed that it is urgent for them to close my loan as i don't want the debit order to go off as the loan was already settled. They told me, only then (23/11/2020) that they owe my R900 odd rands which i overpaid! I asked the lady to just close my loan or stop the debit order and she said she cannot do that until my money is refunded into my account. When i asked to speak to the manager they told me they cannot put me through to the manager as they work remotely. Mind you, i had the same problem with Nedbank and they got someone to close my loan in 1 day (Yesterday in fact) and stopped my debit order and they gave me my refund (as i also overpaid) I asked FNB why they didn't call me to tell me that they owed me money and the lady told me that i should have checked!!! How the hell should i know i overpaid my loan! In my last attempt i went down to the branch and they didn't even assist. I stood in front of a que for 45min (my entire lunch) and went back to work as it was taking way too long. I called one last time and fumed but all he could tell me is that the debit order will go off. if it goes off they can refund me but protocol stipulates that i will have to wait another 4 to 7 days!!!! So in a nutshell, i cannot close my loan until they refunded me and this takes about 4 to 7 days. My debit order will still go off regardless if my loan is paid off!!! and then after i get my refund i must fight for the debit order that goes off tomorrow that's not even supposed to. I am a very angry customer! And i know there is someone that has the authority to close my account as it was possible with Nedbank.