Absa Homeloans: Poor Service

I have paid up my 15 years homeloans months ago and have decided to leave the home account open for rainy days. On the 24 of May 2021 I transferred out R90k and on the 28 May 2021 I transferred out R71k. To my surprise on the 1st June I already had a charge R10 for an unpaid instalment and there was no evidence of what was the instalment. To my surprise there was another debit order run on the 10th of June 2021 and the debit order returned because the there were insufficient funds to cover your debit order amount. Not that there was no money to cover the instalment but based on the amount owing I made sure that there was money in my account to cover for that.

Can someone please explain to me how was the monthly installment calculated to be R2700 on R160k owing amount at 7.35% interest. And when the first debit order failed it would have been a courtesy for absa to make me aware that they will be running a debit for a specific amount on a particular day but absa as usual is about making money with poor customer service.

I will not allow absa to mess up my credit record with your poor processes. Please ensure that this does not reflect negatively on my credit profile and please adjust my instalment accordingly.