Don't worry! If you have linked your game to an account (registered with your email), you just have to pass the tutorial once again and tap the "Free" menu as soon as it's available.
In the "Free" menu, tap on the "login or register" button and enter your username and password. Your progress should be back instantly!
If you still cannot restore your progress, you may need to ask Support to reconnect your game. Please open a support ticket using our in-app Help & Support page. Make sure to send us your Player ID and the account you used to log in.