If you subscribed to Grokker through iTunes/Apple it is managed completely by Apple. Therefore, you must cancel your membership through Apple.
You can do this on your mobile device by:
- Access Settings in the home of your device
- Scroll down and tap iTunes Store and AppStore;
- Tap your e-mail and Apple ID, View Apple ID and enter your password;
- Tap Subscription - Manage and select Grokker;
- Turn off the auto-renewal option and tap Done.
If you need further assistance with your Apple subscription Reach out to Apple Customer Support and ask to speak to an Apple Advisor. (Have your Apple ID on hand) You can reach them here: 1-800-275-2273.