I am having spam posted on my Apple calendar. How do I stop this?

I was finally able to divert spam emails away from my inbox but now, after a week, they are showing up as text on my calendar. I am unable to delete these items. They are calendar invites and the only options are “Delete”, “Maybe”, or “Decline”. I don’t want to acknowledge any for fear I’ll validate my information. Any suggestions for how to stop would be appreciated!