double deduction

Best debt finance deducted twice from my capitec account, and they didn't send me a Debi check for me to approve. I requested them to refund at least one amount, and they refused saying they can only refund me R708 of which it is unacceptable. i will them to refund me all my money as i was not notified of this double deduction. I am also considering moving away from capitec as it clearly shows that my money is not safe with them