FNB is charging me for something I don't know..

Dear FNB,

I am being charged many times for #ITEM PAID NO FUNDS 1 ITEMS ON different days. I need my money back as I had funds and my account "Cheque" lets me has a debit and balance the amount later. You make us pay for something that you said cheque account is supposed to do??? Why do we have cheque accounts then??????