See the following Apple articles:
View your purchase history for the App Store, iTunes Store, and other Apple media services
View your purchase history for the App Store, iTunes Store, and other Apple media services - Apple Support
How apps, content, and subscriptions from Apple are billed
How apps, content, and subscriptions from Apple are billed - Apple Support
Request a refund for apps or content that you bought from Apple
Request a refund for apps or content that you bought from Apple - Apple Support
See the following Apple articles:
How to cancel a subscription from Apple
If you want to cancel a subscription from Apple - Apple Support
If the subscription that you want to cancel is not listed
If the subscription that you want to cancel is not listed - Apple Support
Identify legitimate emails from the App Store or iTunes Store
Identify legitimate emails from the App Store or iTunes Store - Apple Support
If you have an invoice from Apple, click Report a proble.