eBay Australia Gift Cards Not Working on International Sellers (Still within eBay.com.au)?

I have come across a huge headache today.
I have found an item on Ebay australia from China, the currency it was listed at was USD. I saved it in my wishlist. The seller made me an offer I could not refuse. So I accepted the offer and proceeded to pay. The offer only works with discounted gift cards I bought previously. So same as any other purchase on ebay, I was going to pay with my gift cards. When I proceeded to pay everything worked fine, but the payment stuck in "pending".

I chatted with ebay customer support a couple of times, but my recent experience is that they will just chat with you but never perform any action whatsoever, so may have been a robot as well.

It is not in pending any more, and dissappeared from my purchases, the system wants me to pay again. But the balance of my gift cards is gone as if I paid succesfully.

So now I am stuck with this purchase I am unable to pay. The seller will not cancel it.

I do not think there could be any easy solution to this problem, but someone might have resolved it? Any advice or recommendation will be appreciated thanks.