I know you will hate hearing it but..... Call them, ask them to review the recorded notations from your July conversation. Ask to speak to the supervisor. Elevate the complaint and seek action. You should have no trouble sorting it out with the right person.
If they tell you they can't ask to speak to their supervisor and keep going up the chain until you can find the person with the power to make a decision. Expect to be on the phone for a good hour or more though. Hands free and loud speaker is your friend. Just keep at it, be patient and make sure you get a decision before you hang up.
I have settle quite a few cases with Telstra in my day. Never lost a case yet. Good luck bud