Why was $19.99 charged for an unknown subscription?

Check your mailbox. Every Apple invoice states what is being billed.

For example: iCloud subscription is being billed.

Hello~ Click on below and review…

View your purchase history for the App Store and other Apple media services - Apple Support

Where are you seeing this charge? Post back if needed and remember we are your fellow forum members…not Apple Support but can point you in the right direction to resolve.

~Katana-San~

• What is the exact description of the charge that you see?
• Do you see it in your Purchase History?

View your purchase history for the App Store and other Apple media services - Apple Support

• You can view and cancel your subscriptions here:

View or cancel app subscriptions on iPhone - Apple Support