Nedbank charging wrongfully! AGAIN!

I have several accounts with Nedbank. My cheque account is the one I use for day to day transacting so I always keep track of it. I have been extra careful lately because I am trying to bring up my credit score so I can have better interest rates when I apply for a bond next year. But it just so happened that Nedbank had ideas. Not aware that their banking fees were due soon, I had transferred just enough money for the transactions that I knew I had done on the account so I would not be overdrawn. But by some odd fate that transaction took so long to go through and after the transfer to cover the transactions went through, I stopped keeping track of the account because I thought everything was in order. Unfortunately, it was not the case. Nedbank had kept back that transaction and put through their bank charges with no notification what so ever! So now, I have been charged for not providing for the transaction, which I could have done if I was notified. Now I have this thing on my bank statement that makes me appear irresponsible! Please rectify this! I made transfer from my other account to rectify the situation because I wanted to make things right but I feel really offended!