Wesbank and FNB unauthorized debit orders

Wesbank debited my account without my concerns and charged me R195.00 because my account did not have funds in it, I called them and there was not response and mailed them still no response to date. I heard of such things but never took them serious about the bank but not that it really happened to me I am thinking twice banking with FNB now and I had the account since 16 year what it was BOP T account to graduates and now. How does FNB allow unauthorized debit orders just like that and each time we consumer have to pay the penalty fees for it and I cannot do anything about it