Hello,
Hope you are doing well. I am sorry for the experience you had with the subscription and its charges.
Mobile-based subscriptions are something that is dealt with by the store team through which the subscription was availed.
[ For example, if you are an Apple user, the ones looking after the payment and subscription are App Store and not Adobe.]
I would suggest you to contact the store once to get the refund initiated from them. You can click the link to learn more:
For iOS: Manage Subscriptions — Acrobat for iOS Help (adobe.com)
For Android: Subscription Services — Acrobat for Android Help (adobe.com)
Let me know if this helps.
Thanks,
Souvik.