Interest in advance – St george bank unable to proces in time -legal options

Hi, I have been paying interest in advance for the past four years on my property. I pay every year near the end of the financial year. This year I did the same – I fixed my home loan via  my bank stgeorge bank. I did this well within time via a st George bank branch –they put in the application and submitted it on my behalf. I have sufficient money in my account all the time (another st George bank account) to take the money out of.

After that I rang up st George to confirm that everything is in place (at the beginning of the month -June) the lady on the phone told me everything was in place and money would be taken out on the 28^th June. I rang up 29^th June morning and they said sorry –system error it will get taken on 29^th June night . The daily routine continued till the 1^st july. Still the same message from a different person on the phone everytime.

 A)     I have an email from st George bank teller that they had a system error and this will get corrected and correctly dated.

Now st goerge bank writes to me saying that they were unable process the interest in advance –sorry.

My loss : Given this is clearly St George banks error that are my legal options –  It would cost me approximately a 10000 tax hit because of this error on part of the bank.