DirectAxis owes me money!

I paid my last and final debit order on 25/10/2019 of R1 055.33. There was a credit on my account of R96.05 and I have phoned 7 different times and spoken to 7 different people about refunding me my credit amount. They keep saying there is no credit amount and while I wait on the phone to speak to the team leader, they cut me off. They also cannot explain to me what "Advance amount" means. The statement that was sent to me by DirectAxis clearly states there is a credit. They refuse to give me my money. If they do this with 1 000 people, they will have nice Christmas bonuses! Details according to my latest statement: Date Commenced : 2016/10/04 Expiry Date : 2019/10/25 Instalment Due Date : 2019/10/25 Instalment Due Amount : R 1,055.33 - Advance Amount : R 96.05 + Arrear Amount : R 0.00 * Amount Due : R 959.28 Other Instalments Due : None According to the above info, the Amount due (R959.28) and the amount taken off my bank via debit order (R1 055.33) does not correlate and means they took more money than they were supposed to