Credit record unfairly ruined by FNB

I took a loan of R100 000 on the 8th of December 2022 and called to cancel it on the 12th December 2022. The cancelation was successful as the 7 days period have not yet passed. Apparently once you get a loan and return it you get blacklisted for a month on other credit providers and the credit bureau. According to Eugene ( FNB representative) who I spoke today, FNB clears everything on their side after 30 days of returning the money, but they don't go back to the credit bureau and update it. Which means ive been blacklisted as if aim the bad payer for almost 5 months now. For that same reason, I cannot get a loan, car or even apply for a house anywhere now. What is more painful and frustrating is the fact that after calling them today to let them know of my challenge, they cannot assist me. They can only give me a paid up letter but the red flag on my name cannot be removed. I'll have to wait for another 30 days for my name to be cleared.

I've been been banking with FNB for over 10 years now, I do everything with them ( home loan, car finance etc) and I have never missed even one payment whenever I owe them. But lately this bank is not only failing me, but is ruining my life as I can not do anything to improve my life because of their negligence.

Can they please clear my name as soon as possible, I cannot wait for 30 days!!!