FNB Personal Loan - Poor Customer Service and assistance

Kindly note that email received was just a response to my complaint.i responded to that email as i made an arrangement to pay off the arrears and this i did on the FNB app on the 27th August and confirmed it with the collections department on the 29th august telephonically that every month i will pay extra until the arrears are up to date and on the 29th August the consultant i spoke to advise that unauthorised debits will not happen again as i have made an arrangement but yet on the 25th September the full arrears amount was debited and even tho had i made trf towards the arrears as well. I called in since monday first they told me all the amounts was not reflecting and that once it is i should call back i called twice yesterday as well as this morning and everytime i speak to a different person they say ok they will request a refund yet the first person i spoke to yesterday morning said the Team leader will escalate the matter as i had a payment arrangment in place because you guys just debited my account with cause my other debit orders to go unpaid. i called again in this morning and i asked them to call me back and they just said they cant and said they will request a refund but i was told yesterday morning already that the matter had been escalated? yesterday afternoon i asked the consultant to provide me with feedback still no repsonse and or a response to the above email i sent yesterday. this is so wrong what was the point of me making a payment arrangement if you guys will just debit my account however you want to? and that is not right as the amount taken is way more than the debit order mandate and i made a payment arrangement!