I've re-read your message - you ware saying to "fix" your problem, not the game. I agree, in this case it is a bit rude response, I had to read your message more carefully to notice this slight difference. There are dozens of people nuking their progress and first thing they usually do is blame the developer and demand something, because they've watched ads / purchased something in the game (and usually believe I owe them) - it just so happened that your message looked very similarly to what they usually write, and yes, your second message also mentiones purchases.

Now, speaking of your lost progress: if you are not using any kind of account, there's nothing to link your progress to. It has been stored on your hard drive, and now it does not exist anywhere.
I've explained how saved games work here: https://infinitode.prineside.com/?m=game_terms_and_conditions
Not sure how you've used Google Play but not Prineside account - Google Play is used to sign in to Prineside account, so if you don't have one - you actually never used Google Play in this game.

The notice message is shown permanently in the main menu, also the game will additionally show a tooltip and will ask to sign in if you have some progress.
Without an account, it is just a regular game - something like Assasin's Creed 2 or NFS Most Wanted, people never contacted EA or Ubistoft asking to restore their saved game, but these days players are so used to services and server-tied games so much they forgot how regular games should work in the first place.