ITEM PAID NO FUNDS

I have an account with FNB, I have been charged R3400 for #ITEM PAID NO FUNDS 1 ITEMS ON . I dont understand why we are charged something we dont know about. You make us pay for something that you said cheque account is suppose to do? Why do we have cheque accounts then? Its better to move my account to a fear Bank that does not take our money for the service already paid for. You have become the worst Bank ever these days.... your charges are too much for nothing. Your consultants are bad in solving this issue.