Unfair penalty charges

FNB charged me penalties for toll fees transactions that were swiped but not processed immediately. I tried to swipe my Petrocard which is normally used for these transactions, but it kept declining, even though it works everywhere else... So being halfway between home and Mpumalanga, I had to swipe my Debit Card to go through, and since it didn't decline I assumed there should be money in my account. After that weekend when I logged in and saw my account was in a negative balance, I immediately transfered between from another account to ensure I don't get charged penalties. Even though I tried to avoid this, FNB charged me 4 penalties of R150 each!! R600 extra over my toll fees and all because their Petrocard was declining at the TRAC toll stations!! When calling them to dispute this I got the usual "we can't help you here sir, you need to dispute the transactions" which I did, and after more than 72 hours I have STILL NOT been contacted for this to be sorted out. This is really frustrating FNB, and I need this resolved and my money reimbursed ASAP