Each of these is a refusal this regime lets a counterparty attempt, paired with the answer to it. Reading them before you write is worth more than any amount of polish on the letter itself.
"You agreed to the terms, which set out the renewal"
high likelihoodThe trader points at a terms page or a single acceptance checkbox at signup.
What answers it
Acceptance of general terms is not the same as informed consent to an automatic renewal, and in most of these jurisdictions the renewal term has to be presented clearly and close to the point of consent rather than behind a link. Ask the trader to produce the actual screen you were shown, with the date. If it produces today's checkout flow rather than the one in force when you signed up, say so.
Federal Competition and Consumer Protection Act 2018 — the consumer's right to information, the prohibition on unfair and unconscionable conduct, and the Commission's complaint and enforcement powers
"Cancellation has to be done by telephone"
high likelihoodThe trader accepts online signups and insists on a phone call, a physical letter or an in-person visit to cancel.
What answers it
Even without a dedicated rule requiring symmetric cancellation, a cancellation process designed to be materially harder than the signup is capable of being an unfair or misleading practice, and it is treated as one by regulators across this region. Separately, and more usefully, you do not need the trader's cooperation to stop the money: revoke the payment authority at the bank.
Federal Competition and Consumer Protection Act 2018 — the consumer's right to information, the prohibition on unfair and unconscionable conduct, and the Commission's complaint and enforcement powers
"You have to give a notice period, so the next charge stands"
medium likelihoodThe trader accepts the cancellation but insists on a further billing cycle under a notice clause buried in the terms.
What answers it
Ask for the clause, by number, and ask when and how it was brought to your attention. A notice period that was not clearly disclosed before you contracted is vulnerable as an unfair term in most of these jurisdictions, and a notice period longer than the billing cycle itself is vulnerable almost everywhere. Pay nothing pending the answer and revoke the payment authority.
"We are established abroad, so your consumer law does not apply"
medium likelihoodThe trader is incorporated elsewhere and says the contract is governed by the law of its own seat.
What answers it
A choice-of-law clause in a consumer contract does not usually deprive a consumer of the protection of the mandatory rules of the country they live in, and a trader that directs its activities at consumers in a country generally answers to that country's consumer regulator. Say where you live, say that you contracted from there, and copy the regulator named in this result. Meanwhile the payment route works regardless of governing law.