RachelRoyle
If this is regarding the Pro version license:
Paying twice with the same Google account cannot happen. If you paid twice, then this was with two different Google accounts. The "Google account" selection is handled by the Android OS and the Play Store app - I (the app) cannot select a particular one when you are signed in with multiple ones. I would recommend to create a database backup, then make sure you are signed in with the correct one in the Play Store app, and then re-download the app.
If your question is about your journal data:
You can simply connect to the Google account of your choice when setting up the Cloud Sync. To switch to another account, use the "reset login credentials" button and then sign in again