Too large debit order taken and now struggling to get my money back!

I paid in a bulk amount to settle my loan but I short paid of R65. So there was only R65 left payable on the loan and they took a R555 debit order. I informed them on 2 Feb. It took them until 6 Feb to confirm that it will take 7-14 working days to refund. It has now been 17 working days with no refund. When they give you a loan they pay out within 24hrs. But now that they actually owe you your own money there is NO SERVICE!!!!