Struggling to get refund and still debited my acc

i paid R10 000 instead of R5 000. 2 x R5000 deposits. the course cost R7200 and they telling me that the turnaround time for them to refund me the overpaid amount is three months. i asked them to cancel the debit order agreement on the 13 August 2015 as i have already paid the total amount and extra, they didnt cancel. yesterday i get a message from the bank that Damelin debited R2200 from my accounts. all they did to me is to milk my last cents and give me disgusting and horrible service since the start of our engagement. I WANT MY MONEY PLEASE. you need to relook at your refund policy - disgusting. please tell me who was supposed to cancel the debit order and just decided not to because is not his/her bank account. people must just learn to do what their employer is paying them to do. REFUND ME MY MONEY!!! IT IS MINE NOT YOURS AND I AM CAPABLE OF KEEPING IT MYSELF. I DONT NEED A KEEPER.