Account debited twice

I have a student loan with which I have been paying for the past 2 and half years through debit order. Yesterday, 24th May my account got debited with R2101 and today the 25th of May my account got debited again. The debit order date as per usual is the 25th of each month. I have called the call centres and they told me that they do not reverse standard bank debit orders. They transfered me to various departments until i hang up since no one knows how to do their job. Now i need to pay rent today and i do not have enough money because of standard bank. I am disapointed.