it thinks I changed devices, but didn't (account lost)

I just signed up a few days ago.

Last night, the game displayed a message, something about it has detected that I've changed devices, and it asked me if I want to migrate my account or something. I hit "Decline" because I haven't changed devices. All seemed fine, until earlier today when I started the game up, it shows me a login screen with "Sign Up" or "I already have an account"...

Obviously, I already have an account... somewhere. I know my username, but I never set up an email or a password or anything. So how do I get access to my account back?

Also, what can cause it to think I've changed devices when I haven't?

Hello,

Please send an email at contact@citydomination.com providing me with your username and more details about your problem, we will see what we can do