App advertised 3 weeks trial period, but after I agreed I was charged after just 3 days. Please refund, I didn't agree to the subscription
Did you take the subscription at the app store? If you did, you should cancel there and ask the app store for the refund.
I hope you are doing well. I am sorry for your experience with Adobe Scan.
Since Adobe Scan Pack is a mobile-based subscription, I suggest you contact the store from where you purchased the subscription.
You may refer to the below links for more.
Our help article to learn more: Manage Subscriptions — Adobe Scan for Android
Initiate refund from the store: Request a refund on Google Play - Google Play Help
Our help article to learn more: Manage subscriptions — Adobe Scan for iOS
Initiate refund from the store: Request a refund for apps or content you bought from Apple - Apple Support.
Let me know if this helps.