Management has stated that they will include better instructions for posting classified ads, and they will also enable editing the thread so that you will be able to change the status. Naturally, this will take a bit of time to implement, so just relax... We'll get it done eventually.
In the meanwhile, I can offer some explanations and history. A long time ago, users could go back and edit their content, regardless of the age of the post. At some point in time, Darin (the owner), limited the allowed time for editing a post to just a few hours. Since then, that "edit" period has been extended greatly, but you still lose the ability to edit your posts after enough time has passed.
I think this is what occurred with your post here; it got too old before you attempted to change or delete, and then you couldn't. Your petitions to get it changed through moderation has reached the point where the classified section will have improved features, and hopefully a better experience.