Fnb charges R85 for a debit order of R12 for no funds available

A debit order of R12 was deducted of my account for a debit order that was not supposed to go off then FNB CHARGES ME R85 FOR NO FUNDS AVAILABLE. THIS IS REALLY RIDICULOUS. HOW MANY CUSTOMERS IS ****** WITH THIS KIND OF DEBIT ORDERS THAT IS NOT SUPPOSED TO GO OFF .CLIENTS ARE ****** OF MILLIONS EACH DAY.THIS IS RIDICULOUS.