Flight date transfer confirmed on website but never went through

My sister booked a flight, then changed the flight online on the 19th of March 2011 (the flight was meant to be on the 21st March and she changed it to May 2nd) and the website had a confirmation screen that came up with a reference number (she didn't write this down) and she was told the change was successful and everything was confirmed. She didn't check until today to see what time her deferred flight was to fly out, and rang up the contact centre today to confirm, only to be told that in fact she was a no-show for her original flight and would have to buy a new flight entirely!

Upon asking to speak to the staff member's supervisor, she was put on hold for over fifteen minutes and then ended up speaking to the same staff member. When she did finally get put through to the supervisor, he didn't care about her problem and told her there was nothing he could do. She was on the phone for a total of and hour and a half.

I have just rung up again on her behalf because quite frankly, she lost her temper the first time and has had enough, and I was on the phone for an hour and a half. I will admit that the lady I spoke to was very kind and undertsanding, however again I got nowhere with her and she kept asking me for documentation to prove that we had been charged the extra charge to change the flight. To be honest, my Mum paid for it and she hasn't checked yet to see if she did get charged, and my sister never received a confirmation email to see if her flight was changed. If my mum was not charged, then I have no documentation at all (which they kept asking for again and again) to show that my sister ever changed her flight and was not a no-show. However, we were more than happy to pay the extra money to change the flight, and wanted to change it to May 2nd 2011, as it is our eldest sister's wedding that we need to fly back from. We may not have been charged the extra because of the site's failure to deduct the money and make the change, despite the "confirmation" screen having been displayed when my sister changed her flight, but we do not feel that we should have to pay for a brand new flight and thus spend another $70 or $80.

They have no email address to contact, and after being told to fill out a "customer feedback form" and promptly doing so, it didn't send as there was another website error. I tried three times to send it but to no avail. I have had enough and if I do not hear back from somebody regarding this mess and the situation isn't somewhat rectified I am going to contact Fair Go and the Commerce Commission.