If you had uninstalled then reinstalled the app you might get a new account, that you might notice the following changes:
Account name
Level
No friends
In such cases if you had a verified account or the account is connected to Facebook, you can recover it by:
Go to settings
Press on “Switch Account”
Click on the method you had connected your account with.
Note: if the account is not connected we advise you to contact our support team for further assistance