Money taken from my account

I'm Charmaine and I have a personal loan with nedbank and made arrangements with them to deduct my arrears of 2 months earlier in the year as I was unemployed at that time the last installment for my arrears was on the 25th of May. Yesterday the 28th a R320 was deducted so I phoned in to the personal loans department I spoke to Augistine who told me that it was a system glitch at that time I was calm and asked them to kindly refund the amount back to my account which it was, yesterday evening at 21:00 another amount was deducted of R657, 59 I called the complaints department where I was assisted by Dumi who I expressed my concerns to.I was upset and obviously wanted answers he stopped me and went off at me saying that I had my chance to speak and went on about how he only takes the complaints and cannot assist me and someone will call me he futher insulted me with regards to my account with nedbank so I told him I am recording our conversation and he told me they are also recording on their side this is poor service they cannot answer me as to why money is being deducted from my account without my knowledge and I still havent received my money back at this time and no call no explanation nothing can someone please advise me what to do with regards to this or who I can speak to.