African bank want to rob me

had a loan with african bank.payed the loan up and 15 june 2019 i had finished paying as it was my last installment .i went to the bank to confirm and it showed.28 june Unisa had a deadline for payments as per the unisa site i then rushed and reversed the june payment and payed the outstanding 1000 to unisa and went inside african bank to deposit back 1500. upon arriving inside the branch in cornubia a consultant by the name of nhlazeko attended to me and started punching my details on the system.the information showed that i had reversed the last installment where my debt was payed up by the amount of R2,223 roughly. well i payed back the 1500 and my debt was R700 and something for july. upon enquiring from the guy at the branch how they will deduct the 700 and something the following month,he transfered me to the guy on the phone.the guy on the phone was very fast and rude but confirmed the figures owed.but the problem was he said they could not deduct 700 and something but the full installment amount with which they will pay me back the difference. in the month of july the bank did not deduct.month of august the bank sends me a statement with roughly R3,146 some change which i must pay.upon enquiring they do not know what happened but i need to have the evidence of what i am saying.i went back to the bank at cornubia mall in durban, went to the same nhlanzeko who helped me last time the he punched my details saw the information was also suprised by the change of figures augus.he again picked up the phone and called up there i dont know where.they lodged a complain for me. the enquiry.the bank have been looking at my complaint since 17 august and the last sms from them that they are looking at my complaint was 23 august 2019. after that i recieved a call at work from the bank to say they cant find me on the phone.i told her my phone was opened.she said but the outstanding amount is small now with which i told her i get that but its not the reflection of 28 june,she told me she listened to the recorded conversation and heard me speaking to the guy of 17 august,i asked her to listen to the one of 28 june 2019 which she mentioned nothing about as that one is definately clear of the amount owed as the guy i was communicating to was reading on the system as we spoke. i informed the lady 22 august a lady called me i was in a noisy place i told her to call me abit later please as this was a very serious matter to not fully understand the other person with which she agreed but never called instead i was told my complaint have been closed and i must call the bank or send them a callback.i need help with this immediately please. as i keep being told i dont have evidence hence that day i never printed anything as i trusted the bank ofcouse,but if the bank is transparent enough they can releasse the recording of 28 june also as it can support my statement and i pay what is truly owed and we separate ways.