No Response to urgent queries

My passport was ****** and I could not get a new passport in time to catch a flight to Wellington, via Sydney on 5/9/2015. I have been trying to get hold of Budget Air since 2nd September to either cancel or reschedule my flight. No telephone numbers are listed online, only an email address. 4 emails later, I still have no response, except for an automated acknowledgement of my email and a promise to respond to me within 24 hours. Qantas, are unable to help me because the flight booking was done online. They gave me telephone numbers to try but these were also unsuccessful. 4 voice messages were left by my mother and there has been no response. What is my recourse to action since the flight is due to depart from OR Tambo today? This is disgusting service!