All transactions are handled by the platform stores. Please contact the dedicated Support Team directly to request a refund for accidental or unauthorized purchases.
Android
Google Play processes all in-game purchases. To request a refund, please get in touch with their Support Team: Google Play Support
Here's an article on how to request a refund for a Google Play purchase: https://plrm.me/refundandroid
In case your purchase was unauthorized, please check this article on how to report unauthorized charges: http://plrm.me/392fgql
Tips on how to avoid accidental purchases: http://plrm.me/3r72YDm
Here are some tips to prevent underage purchases in the future:
iOS
Purchases made in the App Store are processed by Apple, and their Support Team is the best place to request a refund: Apple Support
Here's an article on how to request a refund for an App Store purchase: https://support.apple.com/en-us/118223
Tips on how to avoid accidental purchases: https://support.apple.com/en-us/HT204396
Here are the articles with some tips to prevent Underage Purchases in the future: