Standard Bank negatively impacting its customers credit records - Pure defamation!

I changed my direct debit details for my Standard Bank home loan from ABSA to Standard Bank in September 2023 and as a result Standard Bank failed to collect the monthly home loan payment so I had to settle the amount manually. Standard Bank have since put a negative credit penalty rating against my credit record as a result of this. I am left with this negative rating for the next 5 years like a prison sentence against my credit rating. I have tried calling Standard Bank home loans and customer services who keep transferring me between departments not resolving the issue. I have been on hold waiting in endless queues with no resolution in sight. Standard Bank are happy to put negative credit ratings against their customers without first consulting with them. In this case, I have a negative credit rating from Standard Bank on my credit record for the next 5 years just for changing my direct debit details. I will continue to call Standard Bank until they remove this negative credit rating as this is pure Defamation of my credit rating for the consequences of changing my direct debit details.