We're really sorry to hear that, we completely understand how frustrating it can be to lose progress. Unfortunately, there is no way for us to retrieve lost data as everything is stored in the cloud by Google or Apple directly.

When reinstalling the game or installing it on another device, it is necessary to make sure that you are connected to your cloud account in-game and wait until the synchronization is complete before playing. 

If you're playing on Android, it might be a connection issue with Google Play. If you go to the Google Play Games (not Google Play Store) app settings, you should find a "Change account for games section". In this section, there is an option to "Change account by game" in which you should be able to select the game, and it will open a window. If the window indicates "Signed out" under the title of the game, this might be the problem. You can then select the address with which you used to be signed in and the synchronization might work again.