African Bank repetitively increases the settlement amount each month, despite my payment of each amount in full. Very bad bank to deal with.

Been paying a personal loan off for years. Finally left with a settlement amount of R870. I settled the R870. No paid up letter issued, instead more money is demanded from me for the next 3 months. The matter was escalated internally but still kept on increasing the debt in thousands of rands despite my paying the settlement amount each month.