Earlier quoted context omitted.
> to have "cancelled 3 months ago, but for some reason we're still billing them" or to just plain decide that the last six months of charges were fraudulent I've had both of these things happen as a consumer. Coschedule kept billing me for six months after I cancelled (and my accounts administrator didn't know we'd cancelled), and I had Experian in the UK continue billing me for six months after they'd disabled my ac…
I do have the occasional customer claim to have "cancelled 3 months ago" via email. We keep good records of such things, so we know him to be mistaken but I always make a point of apologizing and issuing an immediate refund. I word my "Why did you open a chargeback" mails the same way, and offer to handle things via a refund (and to please close the dispute because it affects our business). But the people who use the…
Your current course of action is probably still best for your business and sanity, though. Hmm...
I assume you send an invoice/receipt email every month by default, to reduce the chance that a user forgot to cancel and to make it easier for those that wish to. (If not, I think Stripe Billing offers this, though I'm not sure...)
(disclaimer, I work at Stripe, though not on Radar or Billing, thoughts my own, etc)