If Apple billed your SuperGrok subscription by mistake, you can request a...

https://riversinterestingthoughtss.wpsuo.com/how-do-i-stop-supergrok-from-auto-renewing-on-ipad

If Apple billed your SuperGrok subscription by mistake, you can request a refund at reportaproblem.apple.com. Go to the iOS Subscriptions section, find SuperGrok, and submit your refund request