FNB DEBIT PURCHASES DELAYED. NOT ACCEPTABLE!!!

I am extremely disappointed and frustrated with FNB. It seems like there is a major problem with their debit card purchases being delayed and that affects one's account drastically. My husband's bank account is in a minus R1241 all because of FNB and all that they do is send a msg on the app saying sorry for the delayed debit purchases. This is not acceptable. One moment you have R1990 in your account and the next a minus R1220. Some of us work on a budget and earn a normal salary, we do not get thousands of rands per month. So when you check your balance, now you must also check pending debits before assuming that is the amount you really have left. This is NOT ACCEPTABLE!!!! Maybe for a business owner but NOT an individual that earns a normal salary!!!!