If you have been unable to get it resolved. You could also try escalating it to the office of the CEO:
https://service.telstra.com.au/customer/general/forms/contact-ceo-form?red=/abouttelstra/contact-us/contact-office-ceo/
https://service.telstra.com.au/customer/general/forms/contact-ceo-form?red=/abouttelstra/contact-us/contact-office-ceo/
