File a formal written complaint and give them 28 days notice to make you whole.
Consumer affairs will ask you to do this anyway so get on it.
Write a letter and physically mail it addressed to “General Legal Counsel” at head office using tracking
Keep a copy ( If you have an address to email, email it as well, but these companies often hide useful email addresses because they don’t want formal complaints )
As the heading or email subject put “letter before action”
Put a plan and factual timeline together including dates and what you were told.
Finish up with what you want and the legal basis for your belief. Give a reasonable time by which you want a response, otherwise you’ll take action including a formal complaint to consumer affairs and VCAT. Give them an email address to contact you at, its faster and easier for them and you at this point if you can email each other