Nedbank HORRIBLE workmanship - Payment Arrangement More than Agreement

Nedbank has done it again, by debiting more than the payment arrangement I have with them, I was told in July 2020 that the arrangement I have made will last until October 202, it`s now only September, but they have debit more than the arrangement, when I first call them I put throw collection department, the that lady just went silence even the line was very silence, but I could see someone is still on line, because the time was still running. Now I had to drop and call again, this time the guy didn`t even give me any explanation, The only thing he said was they were going to refund me the extra money that was debited.