Difficult to get service due to lack of staff

I called in at the FNB branch of FNB on 2 May as I was unable to adjust my limits. When I logged in on their system I was told that the cardholder - me - was not authorised to use the card! I have now just received an email saying I am being charged for My Limit Alert which I never authorised nor did I request. I have jhust called the number and after holding on for some time was told that they have to find ouot what is going on. Please can anyone at FNB give me an answer and nolt charge me for something I didnt ask for! Thank you