Funds taken out of my bank account without notification

I'm totally annoyed with Nedbank personal loans department as I'm aware that my account is in arrears however I made arrangement for payment every month with a lower amount of my installment and I had my medical debit order and my fees to travel to jhb for a conference on the 7th of September... with no notification on the 2nd of September I chk my bank statement and I see money taken out and then I kotice its nedbank. I wait for Monday to call them and to my surprise they took out and R2638 .... I'm so disgusted as if u had the money my account would be up to date... I'm financially unstable at the moment hence I have an arrangement and it's not as if I'm not paying at all.... I called spoke to Lorenzo and a lady...