calendar full with this recurring event
Assuming this is a Google Calendar, the following advice from https://the-parallax.com/2018/05/11/how-to-stop-calendar-spam/ should help:


  Google Calendar: From a Web browser, click on the event in Calendar, but be careful not to reply to it, and not to click on any
  of the links within it. At the top, under the Going section, click
  “Report spam.” The event, along with all others from that organizer,
  will be removed from your Calendar.
  
  To prevent more spam from showing up on your Google Calendar in the
  future, click the Gear icon in the upper-right corner, and go to
  Settings. Scroll down to Event Settings, and change Automatically Add
  Invitations to, “No, only show invitations to which I have responded.”