@social_calmness9623 I hate to say it, but because you bought Acrobat Reader on your mobile device, it isn't likely Adobe who is charging you, its means the transaction was handled by the platform's native store, not Adobe directly. You are essentially making an "In-App Purchase." The payment method on file is charged by either Apple, or Google, who then remit a portion of the payment to Adobe.
To cancel a Reader Mobile subscription, you must cancel through the app store where you subscribed—it will depend on the mobile device, Google Play for Android, Apple App Store for iPhones/iPads: