You can delete your Hay account in the app:
Android
Profile → Settings → About Hay → Delete account. Type DELETE in capitals to confirm.
iOS
Me → About Hay → Delete account. Type DELETE in capitals to confirm.
You can sign back in within about 30 days to cancel the deletion. After that the account is permanently removed.
Deleting the app or the Hay account does not cancel a store subscription. Cancel that in Google Play or the App Store.
Reply with your user ID so an agent can look this up.