I accidently pay for one year.... 69 €....

@baptiste_9152 A refund depends on when you cancel and the type of subscription you purchased. Now, if you are a past user have used a trial versions and then cancel it, the company may not cancel it and charge you for the app. Because this post is from Acrobat Reader Mobile, this would mean you may have made the purchase on your mobile device may it be Google Play Store or Apple App store, you need to contact thm directly. Adobe does not have access to your accounts and billings. 

Here’s how to cancel based on your subscription type:

On Android: Use our automated cancellation form to submit your request. It only takes a few moments.
On iOS (iPhone or iPad): To cancel your subscription, follow the instructions outlined in the help article.

https://community.adobe.com/t5/adobe-scan-discussions/how-to-cancel-acrobat-mobile-or-scan-premium-subscriptions/td-p/15427706