Cancelling items

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Can someone please tell me how to delete an item once it has been rehomed? I have tried multiple times, clicking on OK when asked if I'm sure I want to cancel and just going round in circles but the post is still up there! Obviously there are others in the same situation, as items are marked as taken, not removed from the site. It would tidy up the site to have taken items removed, so where's the problem in being allowed to do so??