Standard Bank Personal Loan department ,Erroneous system issues not solved

I settled a personal loan in the month of November 2020 and the Personal loan department closed the loan on the system in July 2021. The loan currently reflects as default from my part. The error has caused my Ucount rewards to be cancelled and has affected my home loan approval. My credit score has been affected. I have been to branches and no one has come back to me or assisted. I am contemplating legal action because I have no help or assistance from the Bank I keep being told to go to another department for assistance