FNB un authorised debit order dispute process frustrating ( 40 days + debit orders)

an authorised debit order was going through for over a year and when I discovered, I submitted a form which indicated that I wait for 40 days , however the 40 days has lapsed since my submission. FNB has never contacted me and I have send about four emails asking for status and no feedback provided... it feels like I have been ignored or is the issue about the significance of the amount I am claiming..... FNB is allowing third party companies to rob us and protect the companies when authorised debit orders are handled in this manner. arrogant banks should be dealt with decisively... so FNB is too big for their clients now ?