It isn't possible for the Mistplay app to remove units or experience from your account, so if it looks like all of your progress is gone, you must have accidentally created a second account.
Often this happens if a user makes one account using Facebook or Google Signup, and another using a standard email signup. If you remember the login credentials for your original account (username/password, Facebook account, or Google account) , all of your units and XP will still be there when you reconnect. If you used email to sign up but you've forgotten your username or password, you can use this site to get them back
If you require further assistance, you can contact our support staff by selecting "Submit a request" at the top of this page.