money going missing out of my account

I swiped my card at Pick and Pay and it was rejected but stil taken from my account. With many efforts between the bank and pick and pay the came to the conclusion that they charged me double and unfortunately cannot refund me and there is nothing either one can do about it. So why do I have an account with FNB if they cannot look after my money and yet they send advertizing sms's encouraging people to swipe at paces like P&P and the stipulated that they are aware of this problem (which I recorded). My next step is I will go the media(news papers etc) and I will make sure this goes global as I want to warn the public.