Unwilling to refund

I have two debit orders with Capitec. I told them to set it to run on the 30th of every month as I only get my salary the last day of the month.

On the 26/11/2018, both debit orders ran on my account. Luckily I had money available to be deducted. Due to this going off early, I called Capitec to query it. I was told the system is automatic and will take my debit orders when money comes into my account up to 5 days prior to the debit order date. I said it was fine, not to refund me as the debit order had to be paid anyway.

On the 29/11/2018, both debit orders ran again, I immediately called Capitec, and was told that it was a system error on their side as it was not supposed to run again. I was told I would get a full refund of the debit orders. But only one full debit order has been refunded. And not the other.