Hi there,
I accidentally integrated some boards with the wrong Google calendar and I can’t unsync with the calendar unless my client upgrades to the next package level. I’m a newbee user and made an error. Is there a way that support would be able to unsync the account from all calendars so we can start fresh - now that I know what I’m doing! 
Hey @mbisiker
Thanks for posting here and welcome to the community 
I’m not sure I understand the limitation for unsyncing the calendar. Are you not able to do this from these instructions?
You will need to un-sync the current calendar and then sync the new one. Please follow these steps.
Step 1
Click here to access your Google App settings.
Step 2
Under “Apps with account access” click “Manage Apps”.
Choose monday.com and click “Remove Access”.
Step 4
Next, log back in to your monday.com account and follow the steps listed above to sync your Date or Timeline columns with the new Google Calendar.
Step 5
You will be prompted to choose the correct Google account to link. Once you sign in to the correct one, you should be all set!