Maestro Pro
Refunds for subscriptions bought in the app
If you subscribed inside the app, Apple took the payment and Apple decides refunds, so we cannot refund it and our cancellation page will not find it. Ask Apple directly: request a refund for apps or content you bought from Apple.
Apple's page walks you through it. In short, you sign in with the Apple Account that bought the subscription, choose the purchase and say why you want a refund. Apple replies by email with its decision.
To stop the subscription renewing, cancel it in your Apple Account settings. See manage a subscription bought in the app.
Not sure where you bought it? A licence key that arrived by email means you bought on this website, so use the cancellation page. No key, and you subscribed on the paywall inside the app, means Apple.