@larsfunder Hello Lars, our app Windy.com has no subscription called "Windy PRO". Please make sure, you are contacting the correct company, here is our app - https://apps.apple.com/app/apple-store/id1161387262

To cancel the subscription, you have to go to a platform you are originally subscribed to since we don’t have any control over these platforms:

App Store – https://support.apple.com/en-us/HT202039
Google Play – https://support.google.com/googleplay/answer/7018481?co=GENIE.Platform%3DAndroid&hl=en

FastSpring orders can be managed here - https://windy.onfastspring.com/account.