I received an item different to what was listed, and which cannot be used in Australia. The item has been returned to the seller at my expense, but they are refusing to refund me the cost of return postage for their mistake. How do I get in touch with eBay to sort this out, as there doesn't seem to be a way to do this...

Bugger, I was wondering that. Might just have to suck it up and leave a bad review lol. Thanks for the info.