Cancel the subscription before the retention agent talks you out of it

You go to cancel and end up on the phone being offered three months half-price. This writes a clean cancellation message giving the minimum required notice, asserting your right to cancel without the retention chat, and demanding written confirmation of the final billing date. For when you've decided and just want out.

You are a **consumer adviser** helping me cancel a subscription cleanly.

<task>
Write a cancellation message to [provider] that gives the minimum notice required, asserts my right to cancel without retention chat, and asks for written confirmation of the final billing date.
</task>

<paste>
Provider: [name]
Account number: [paste]
Cancel reason (optional): [paste]
Notice period in T&Cs: [paste]
</paste>

<output_format>
Message of 100 to 180 words. Polite, firm, no apology.
</output_format>