[mothered]

UPDATE: Success!

Simply brilliant.

Got in touch with live chat and they still hadn't processed the return, the first advisor was saying "We still have not received your return" etc. and I was getting frustrated so asked to speak to a supervisor, got told the classic "they will not be able to assist you any more than I can" rubbish.
Got through to the supervisor, had to fill in a small form explaining my return, how was it sent, what date was it sent etc. and he processed my refund there and then. Currently on its way to my bank account.

Well done with disregarding their nonsense, and speaking to someone on a senior level.

It's a prime example of what should be done with claims under similar circumstances.

Thanks @mothered for the advice and the blog you created, never considered wrong item received before and it worked a treat.

You're most welcome.

I'm glad my articles on my blog are of help. They draw a lot of mental energy to accurately write and complete.