Charged a penalty debit order fee when I paid the minimum amount due 4 days early.

Your system is a rip-off and makes no sense. You charged me R105 for a bounced debit order when I was told when I signed up for a gold credit card that I could pay my account in-store or via debit order. A debit order was compulsory apparently as a backup. Last month I paid my minimum amount due as I did not have the full amount as I usually do. I paid it 4 days before the debit order was due to go off. You then still try to debit my account when you can see I paid the minimum amount due already. I contacted your credit card department about this and had no joy. Why are you still trying to debit our accounts when we pay instore ? This is ridiculous. Why do you punish clients for paying instore. My payment was on time and via a medium your company says clients can use without prejudice so why are we being punished for using it ?