Paid Unreserved funds

I am extremely disappointing with FNB. Easter weekend i was was traveling and was using my FNB card to pay for tall gates. Two weeks later I'm shocked to find my account over the limit because those toll gate amounts are take out now. To even make thing worse i find that FNB has charged me R110 for unpaid items for each of those toll gates amount. How the HELL do you charge someone unpaid item, when I had funds in my account when i was passing those tall gates. Why were those amount not reserved???>This is nonsense and day light *******> FNB THIS IS UNFAIR AND I WANT MY MONEY BACK. You are messing with peoples life.