Email mustafayevte@gmail.com and you will get a reply from a person.
KNURL is a haptic instrument, so the phone has to be allowed to speak. Check Settings › Sounds & Haptics › System Haptics is on. Haptics are also suppressed while Low Power Mode is active, and they do not exist at all on iPad or in the Simulator — KNURL is an iPhone app for that reason.
New phone, or reinstalled the app? Open the Shop Wall and tap RESTORE A PURCHASE. Make sure you are signed into the same Apple ID that bought it.
Go to Settings › your name › Subscriptions on your device, or tap the manage row on the Shop Wall. Cancelling stops the next renewal; you keep access until the period you already paid for runs out.
The Shop Wall reads its prices live from the App Store, so it needs a connection for that one moment. If it says the counter is shut, tap RETRY. Everything free stays playable regardless.
Feel is the whole product, so a machine that feels off is a real bug. Tell us which machine, which finish, and which iPhone you are on, and it will be looked at.