Over-charges on zero balance settled account

From the start I had issues with their accounts department... I paid extra every month to finish this account as soon as possible as I could see they have no accounting skills and take 5 working days just to reflect a payment on a customer account. On 30/08/2024 I settled my account in full. I emailed the proof of payment to them. I knew my debit order would go off on the 1st but that can be refunded back to I was not too worried. What I did not expect is that they will charge me on the 1ste of September R6.02 for Month-end interest; R43.00 Administration Fee; R4.50 Credit Life (per R1,000 balance) remember my balance is zero at this stage; and R0.36 Adjustment for some reason! So they charged me R53.88 for a zero balance account and then the debit order for R74.50 went off because it was not cancelled 7 working days before the 1st. The debit order I can fully understand. I tried to reason with them; but they are not interested to listen to reason. I reported them at the Ombudsman and will now involve my lawyer as this is a matter of principal to me.