If Apple billed your SuperGrok subscription, head to reportaproblem.apple.com...

https://record-wiki.win/index.php/How_Do_I_Stop_SuperGrok_from_Auto-Renewing_on_iPad%3F

If Apple billed your SuperGrok subscription, head to reportaproblem.apple.com to request a refund. Navigate to iOS Subscriptions, find SuperGrok, and choose the issue