Absa loan

I had a loan with Absa that was paid up in December 2022. No arrears, it is PAID UP. I have the letter to confirm this. Absa is literally harassing me daily, all hours of the day and night, with emails and messages saying I am in arrears, when I have never been in arrears and the loan is fully paid. When I phone their loans department they say they are so sorry, but it is still happening. It is a horrible feeling when you get messages at 2 am at night, you think that something has happened to a family member, and it is Absa. It makes not want to do business with Absa again. I have reported this and it has been escalated but clearly Absa cannot fix this