Double Debited & dissapeared funds!!!!!

My debit order for my credit card goes off on the 23rd of every month; my installment amount for this month was R1165.34 i was shocked & livid to see that FNB had double debited my account on the 23rd. The 1st debit was succesful as per the sms & statement and to my utter dismay i received another sms the following day (24th) stating that i have a return debit from fnb for that called amount, resulting in me being charged an unpaid fee amount by my bank (which i have to pay for by the way) all because this damn bank. I want to know WHY the HELL FNB DOUBLE DEBITED MY DAMN ACCOUNT!!!!!<br> <br> Secondly it is highy impossible & absolutely ridiculous that the very same debited amount of R1165.34 ALL went towards bank charges for this month, as of the 1st of March there is R0 available on my credit card (impossible). I want a detailed account as to where the rest of my money went FNB???<br> <br> I am definitely thinking twice about switching to this bank, there is absolutely no sense of accountability and no one seems to know anything!!