debiting my bank account without my permission

On the 25 August my account was with an amount R941.00 when I called them to ask to reverse the debit they said they will not refund the amount as it was done by their legal department for a Ackermans I had in 2003. what makes me really angry was the attitude of this people , saying basically they will not reverse the debit even though I have not given them permission to do so . I have also had problems with and debit orders from Old Mutual and they charged me in one month 3 x R90. for a debit order I had paid to put a stop . I had gone under debt revue in April, both Nedbank And Old Mutual were made aware of this but they continued to do the same thing for 3 months afterwards and never received my money for all the charges I had to pay in Bank charges . The person I spoke was so rude and told that they will not refund my money. Is this even legal what they are doing.<br> They have not even notified me of this before the time R941 might not be alot , but for me it is money I cannot afford to throw away .