Unfortunately, unless the item had tracking which shows (or will show) the item as delivered, eBay is unlikely to remove it, so the only other practical option would be to contact the buyer and attempt to resolve the issue (which could involve some gentle education re: international postage times, contacting sellers before FB to get issues resolved quickly and amicably etc), and ask them to revise if/when it's resolved, which is not the easiest thing in the world to do at times, for various reasons.

I had a similar situation a while back (new buyer, negged for non-arrival without contact), and I have to admit I didn't take my own advice related above (I was too annoyed with the buyer to attempt that route   though I did refund and express my disappointment over their choice not to contact me first).