Unauthorized debit orders and charge R105 fees

FNB CHARGE ME EVERTIME R105 FOR DEBIT ORDERS THAT I NOT HAVE MANDATED FOR AS THERE IS NOT MONEY AVAILABLE IN MY ACCOUNT.FNB WILL LET DEBIT ORDERS GO FROM MY BANK ACCOUNTS THAT I HAVE NOT GIVE PERSION FOR AND THE WRONG DATES.THIS IS REALLY POOR SERVICES AS THIS IS HOW THEY ****** THEIR CUSTOMERS.