The easiest way to check it is to try to log into the game via or from a different device and choose an option 'Login with Facebook'. Without understanding, you already linked the Facebook with a new account.
There might be several reasons why you are unable to re-link your Facebook account with a new game account. When you requested deletion of all your personal information from our database it was probably expected that all the data, links etc is erased and that you can re-link your Facebook account again with your new game account.
