No benefits for clients, only for the bank

Why are banks such ******. I do not have an overdraft on my Premium cheque account. When I go and buy something I have to have the money for it otherwise it will decline and they will charge me R8, 50 which makes perfect sense. However why charge me R120 and on another occasion R240 for "Items paid"., When did you pay my items. Because when I purchased I had money enough to cover the purchase. Now because the merchant takes time to bank the transaction and my bank charges goes off before the transaction is banked now you want to charge me fees claiming you paid my purchases when technically your bank charges took the money that was reserved for those purchases. Really. So now you expect me to pay you R360 just like that for nothing. FNB does nothing for me in any case. There is no benefits in being a premium client or even a private client. The only party who benefits is the bank because they get to inflate charges