Are you currently running version 2.7.5? That is the version you listed in one of the emails you sent me. Version 2.9.6 is the latest version. All you should need to do to update is to log in to the Google Play Store with the email address you used to purchase the app, search for MobileSheetsPro and tap the update button on the store page. I have responded to your email to get additional information about which account you used to purchase the app.
Mike
Mike