Random no-reply Apple invitations on my iPhone not on Mac pro

Hi there

I have multiple random invitations in my calendar. I click decline, does not remove. They are recurring. They are filling up my iPhone business calendar for work. Frustrating. I called Apple support, we deleted calendar, restarted they were removed for a day and then all came back. No random calendars have been added, we checked.

SOS it’s clogging up calendar … t