FNB duplicating 'reserve funds' transactions

I have had issues with funds being reserved twice on my FNB account since Black Friday. This is an IT problem. I have phoned numerous times, gone into the bank twice, emailed numerous times, logged a card dispute, and had endless secure chats. FNB doesn't seem to understand that this is not *****, it is a technical issue which I suspect they experienced on Black Friday. There are now three amounts which were reserved twice. In other words, even though the vendor only banked the amount once and there has been no '*****'. FNB reserved the amount twice so although the money is in my account I can't access it because it has been taken off my available balance twice.