Charged in error

If you're sure you followed all the steps in the first two articles, then either request a refund from Apple, or if the subscription was not billed through Apple, then from the developer.

View, change, or cancel your subscriptions - Apple Support

Get help with subscriptions not billed through Apple - Apple Support

Request a refund for an App Store or iTunes Store purchase - Apple Support

Apple Support Community Forum

This is Apple Support Community forum, for user to user interaction for information & idea sharing between users, if need be, extend support on technical knowhow in handling Apple products from more experienced fellow user, Apple Inc is neither here nor they are listening. 

Hence, we are unable to help with any of the following:

• Questions directed to Apple Inc
• Hardware repairs & tickets, 
• Service grievances & questions, 
• Warranty & Apple Care+ issues
• Order & Transaction related information, 
• Suggestions and Feedback for improvements
• Shipping & Transportation queries
• Repair costs or product or parts prices,
• Product & Launch Detail etc.. 
• Third party apps and its behaviour

For these questions, you may contact Apple Inc or your local Authorised Apple vendor directly. 

Thank you for your understanding and support.

Contact - Official Apple Support

https://support.apple.com/en-in/contact