Don't be daft. Leave it up. As long as the article is truthful, what's the problem? Their appalling treatment of an honest customer should be exposed.

I do think you're totally overthinking this. They made the initial mistake, they need to correct it and at their expense.

They can't do anything to you. Make a "best effort" to return the item and no more. Keep a log of all your correspondence. Don't waste any more than a minimal amount of time on this, certainly don't take days off work etc to wait for couriers.