FNB *****ing once more

Can someone please explain to me what is the reason for having funds in your account when buying stuff, when FNB waits for all the monthly fees to be deducted then decide to deduct the money I had in my account x2. I made a purchase on the 12th, with funds in my account. 3 days later they take R145 for items not paid. So what the **** happened to the money I bought with????

I need my money reversed today still and then close my account. **** the money I still owe. The account can ma be left in arrears till the account tuens blue. You guys **** with peoples money too much!!!