Shocking service

On the 13th December 2014 I withdrew cash from an ATM and the money did not come out of the machine, I immediately attempted to withdraw the cash again which was then successful. FNB then debited the amount from my account twice. I called them on the 15 December 2014 for assistance which took a few days to resolve and reverse the transaction. On the 29 January 2015 I was credited for the same amount, I then phoned FNB and asked if this was a mistake and they said no it wasn't and they were a 100% sure. On the 11th Feb 2015 I got debited for the amount AGAIN! No one can give me an explanation, no one can assist in resolving this for the last 5 days! I spoke to several different consultants of which no one has the authority to give me an explanation. This is absolutely pathetic service from FNB extremely disappointing and frustrating. Its shocking and worrying that such a big bank can make a mistake like this in 2 seconds and take more than 5 days to actually sort it out.