Get them to open a dispute, you have nothing to lose.
It may call their bluff as well if you place the ball in their court.
They could have done it before too which eBay will know about and if they haven't they will now.
Get eBay to decide what your to do.
You said it was not working which it wasn't.
I would suspect they needed a Blu Ray lead!!!
I am really fed up of eBay, especially buyers buying stuff and not paying and all they get is a non payment strike.
And definitely don't give any money back until you get it back.
Let eBay sort it all thats why you pay fees.
