First National Bank - #ITEM PAID NO FUNDS

First National Bank is the most useless bank every. I would like to start by saying that when I first joined FNB it was an awesome experience, now it has become a costly affair. My account was just debited of R600 rand's for #ITEM PAID NO FUNDS 5 ITEMS ON 18/08/ when at the time there was money in my account, and if there was no funds why did FNB not notify me so that I could transfer money into my account . I only noticed the minus amount when I logged onto to my internet banking stressing out about the #ITEM PAID NO FUNDS penalty, soon to find after I have paid all the amounts they deduct R600 for this . I called into the call centre furious, no help, no valid answers, supervisor told me I need to speak to the company that debited my account reason for the no funds. I honestly think this is ridiculous , and costly, I want to move from FNB but now they say that I cannot because I am paying for the PS4 ? This experience has been very disgusting, and very nerve wrecking. I would really appreciate a refund on my R600 because firstly the penalty should only be enforced if I never paid that amount for several days, how can the penalty come after I have already paid? I need this to be rectified accordingly please.

Please just clarify all of this for me, and if there is any possibility I can receive my R600 back.