unpaying debit orders to generate income

I am very disappointed with the treatment I am getting as an account holder. What is the use of having a cheque account if my debit orders are always getting unpaid and being charged R112-00 without even being given a grace to adjust the account in some instances I have transferred from my savings immediately. most recent a debit was unpaid because the shortfall is less than R2 the i get charged R112-00 how is this allowed is it a way of generating money from a client by making sure that they get charged a lot of R112-00 unless if i should rather downgrade to a Gold Cheque acc which was a better option. Can this be investigated so I know what to do.