I fell victim to this spam, and it was incredibly difficult to get rid of, due to bugs on Google's side. Simply unchecking the box didn't seem to make the invit

I fell victim to this spam, and it was incredibly difficult to get rid of, due to bugs on Google's side. Simply unchecking the box didn't seem to make the invites go away, and I was unable to delete them. Eventually, I used the GCal API to go in and blow everything away. Ugh.