@hello_sport
Hi - are you on Managed Payments yet? If so, is the "order" listed there in "all transactions"? If it is, you will see a payment processing, (which confirms that it was paid), and should be able to click on the order number and see all necessary details for further actions including buyer information. If you buy postage via eBay all buyer info should be there of course. If it is not, then I would cancel the order, using "something wrong with shipping address" as the reason.
If you are not on MP, are you saying that from Seller Hub you are seeing it as both paid and unpaid simultaneously? Very weird. I think my advice would be the same. Go into the "paid" one and cancel it for the same reason. Message the buyer to explain.
