I want my money!!!

I would like some information or help with this matter....l had a few months left to pay off the balance of my ABSA personal loan and since it was a small amount, I decided to pay the whole amount of the balance. The problem is that the monthly debit order amount was deducted from my account even though I now owe the lender nothing. I went to my nearest ABSA branch to ask them for the money that got debited out my account to get credited back and they got my into contact with the consultant telephonically. The lady told me that because I did not call them before I paid off the balance and the monthly billing cycle began I can't get the debited amount back, it cannot be credited back into my account. Is this true? I would like my money back cos if I were to miss a payment on the loan they would have been hounding me for their payment and even handed me to the credit authority, so how is it that I can't get my hard earned money back? This is outrageous!!!