To cancel Grok, make sure you do it through the exact billing channel you first...

https://bizzmarkblog.com/how-do-i-request-an-apple-refund-for-supergrok/

To cancel Grok, make sure you do it through the exact billing channel you first subscribed with—whether that’s grok.com (Stripe), Apple Subscriptions, Google Play, X Premium on x.com, or the console.x.ai portals for Business or API billing