Account Paid & NOT Updated - resulting in harassment

I am tired of the continuous daily harassment over a paid up loan from Standard Bank. For the past 3 months on a daily basis I am being harassed over a Standard Bank account that has been fully paid up and closed. Standard Bank has failed to update their records and communicate with the company to have the account closed on their side. Despite my numerous efforts and back and forth communication with the relevant paid up letter sent to these *****s I am still being harassed. I am being told that Standard Bank still reflects an outstanding balance. My telephonic conversation with Standard Bank refers, the account has been settled however NOT updated from your collections division! This was paid up in November 2019, HOW is it not updated and more importantly WHY? Update your records and confirm with these *****s in writing that this has been settled