FNB LATE PROCESSING OF PURCHASES CAUSES A MINUS ON MY BANK ACCOUNT

I bought KFC on either the 17th or 18th December 2021. There was enough money in my account for the purchase. I mean, really, the order would not even go through if there was not enough money in my account to pay for it. Later in the month, I was wondering about the minus on my account and noticed that FNB had only processed the purchase on the 28th December. Unfortunately, on the 28th December, there was insufficient funds in my account and the R350.00 (approx) purchase was not successful which caused a minus on my account. I want this rectified and reversed. This is not my fault. This is not the first time that something like this has happened. Previously, a purchase of over R1000 was processed late, but that matter was sorted out by the Ombudsman. I expect the R350.00 issue to be sorted out immediately please!