Total BS!!! FNB needs to look after their clients!!!!

I advertised to have my couches sold , a buyer contacted me and ‘seemed’ to be interested. After he paid the amount into my account with a Cheq it bounced. (No surprise there) The amount then puts my account in the minus of the valued paid in with the Cheq. After that I called the bank an they sorted it out but now I have been charges a fee of R320 for this whole dilemma. How is that fair? Am I the one that paid with a faulty cheq? Not to mention, another person paid me again with the same method who I know did it for the same reason and when that bounces I will have to pay the same penalty again! This is BS! As my bank FNB should be protecting me and not be making me pay fees of R320 when the fault does not lie by me!! I want that money transferred back now! Or I am closing my account! That is **************** from my own ban****