I've had this issue for quite some time, but just now getting around to asking about it.
I'm currently running ver 2.1.5 of JEM on a ver 3.9.3 install of Joomla @ matr.nybn.org. Our gaming schedule is nothing but recurring events that are forecasted out for quite a while. Sometimes things change and games get canceled and replaced with new ones. When this happens, I go into JEM's Events section of the Admin area and sort by the name of the event I'm removing, check them all, and Trash them. I'll refresh the list a few times to verify that they're all gone. Come back to the site a few days later and some instances of the old events are populating the calendar again along with the new ones.
How can I go about deleting a recurring event for good without clearing out all of my JEM data via Housekeeping?