FNB Double Debits for online card purchases

With reference to my previous complaint regarding my online card purchases being put through twice each time by FNB, I have still not received an explanation or resolution. Instead they've sent me a Cheque and Debit Card Dispute form. My problem is that this won't fix the obvious bug on FNB's system that allowed this to happen in the first place! If anyone had taken the time to actually view the transactions, they'd see that this is an FNB issue, and that every second transaction was sent without the request or requirement of an OTP. There's no point in me disputing these small amounts if the issue is just going to occur again. I'm just glad it wasn't a larger amount, yet still absolutely shocked that something like this can occur! I want to make it absolutely clear, the issue is not with the merchant, it's FNB that doubled up each transaction seconds apart!