Hi, did you get any resolution with this?
This happened to me as well since I joined AGL last June.
I joined under flat rate (which I preferred), then they change it to ToU without my consent, then they change it back to flat rate and saying that it's a mistake.
Currently my account is "under review" again without my consent. They keep blaming Ausgrid making changes in their policy, which doesn't make sense. Friend of mine is on Ausgrid with AGL flat rate, and they never "review" his account.
Very frustrating as we need to keep adjusting our usage to accommodate rate changes.