Confirming the cancellation
EmailSubject: Your [Product] subscription is cancelled
Hi [Customer name],
Done: your [plan name] subscription is cancelled, and you won't be charged again.
You'll keep full access until [date], the end of the period you've already paid for. After that, your account switches to [free plan / read-only / closed], and your data is kept for [period stated in your policy] in case you come back.
If you'd like to export anything before then, you can do it from [where to export].
If you have a minute, I'd really like to know what made you leave. One line is plenty, and it goes straight to the people who build [Product].
[Agent name]