Cancelled Event Still Showing

We have created some events within iMIS and since then we have cancelled these events, however, they are still showing on our website.

When we try to edit any of the data, such as "Show in search" and "Registration date" (as we think this may be why the events are still showing) we get the following error - Event Status X must be set with the Execute method not the Update method.

Anyone know a solution to this issue?