You can delete your Calendar integration by following these steps:
- Go to calendar.google.com and login with your google account.
- Look for my calendars on the left side of the screen.
- Click on the downfacing arrow and click on settings.
- Now look for a calendar name RosterBuster* and click on unsubscribe.
- Your Calendar intergration is now deleted.
Make sure you've disconnected from the Google calendar live intergration.
*The name of the calendar can be different, because this can be changed on the settings screen on the website.