Hi Linda from rainy Seattle - I think perhaps the reason you wound up with two posted listings is that after you edited the 2pm listing, you probably clicked the 'Schedule' button on the listing page to enter your new posting time of 6:30pm. Rather than simply re-scheduling your listing, this would have scheduled the listing anew, without canceling the original post time. To prevent two postings, you would have had to manually cancel the original post time from the 'Scheduled' folder.
An alternate, and preferred, way to change your scheduled post time is to go to your 'Scheduled' folder, checkmark the listing, then click the 'Edit Post Time' button, and change the time. This would simply re-schedule the listing that has been saved, whether it is original, or edited. If you need to do further editing you can click the 'Edit Listing' button and edit. Just click 'Save' when you're finished, not 'Schedule', since it is already scheduled (unless you want multiple postings). By the way, if you edit a listing that has already been scheduled, after clicking 'Save' you will then get a red notice at the top of the listing page to confirm your save(do this at the bottom of the page). This is because you are saving over a listing that is already scheduled to post.
It is normal for Auctiva to show a listing that was terminated early as still being active. A glitch I suppose. If ebay doesn't refund your fees, I would contact them and request the refund. They will often do that for you, if you are polite. Since ebay is the one charging you, Auctiva has nothing to do with the refund of fees.
I hope this is more clear than all the mud you have been getting in your part of the world.