Please make sure that you are logged in the app itself with the same details - Facebook account and Live ID - you used for registration previously.
Please tap on the Menu=>My account:
If you are logged in the app you will see your Facebook name. If you are not logged, you will see "Login with Facebook" and "Login with Live".
You need to log in with the same details you used for registration before. As soon as you log in, your coins will appear.
If you have started to use a new device and your coins didn’t transfer, please also make sure that you are logged in the app and that you are logged in with your Microsoft account in Windows Store.
If you still unable to restore coins, please feel free to contact us. Click here to submit a new request.