Fnb charges you for their mistakes

Last Thursday 10/10/2019 myself and the kids went to our local supermarket to buy sum small groceries. When I wanted to pay at the till point with my fnb card the transaction didn't want to go through. I tried about 2 times. So while I embarrassed and while other people were waiting impatiently behind us in the que , I ask the cashier if i could go and withdraw from atm and could she keep our groceries aside. We tried the fnb atm twice...nothing.... i then tried capitec nothing so i thought it must be my card cause it didnt dven want to peint out the balance...I them had go to our local FNB branch at Hammersdale to make a new card and get info to find out what is going on. They then told us that the whole of FNB in SA is offline but we can try withdraw money from the ATM but they doubt it.So she did go to the ATM and found a long que of people waiting to also withdraw and said it wae not coming out. So she had to stand for about 30 minutes before she ended up at the ATM to withdraw money. I t Decided to try nedbank. Viola my card works and i withdrew the money and had to quickly go and pay embarrassingly to the cashier.

But know the big question is, what is FNB going to do about this ? We were ****** from our time and we were embarrassed and angry by all this. And why must i pay R7.00 for each failed transaction while we were trying the card ??? Theres like maybe 20 of them.