There are two shipping charges on eBay Global. One is paid to the seller; usually $5-6 to ship to Erlanger KY (their collection point for Overseas), and one eBay collects directly (just like your sales taxes), on what they charge to send overseas. As a Dealer, I can only refund on Domestic shipping, I have NO access to Overseas shipping charges collected. I don't even know what they charged you! Like said on another post, best to put in your Cart, then request total from seller.
Very likely, they can only refund their Domestic shipping, but have no knowledge of Overseas shipping charges. That said, I have no idea how Chinese Government subsidized shipping is handled.
I now use the Global Shipping on overseas somewhat because they self-warrantee delivery: before, too many times buyers would claim they never received items and demand a total refund. Now, I just have to re-direct their claim to eBay.