There seems to be a couple of recent similar threads, I notice, about buyer not recognising the transaction.
The same has happened with me, but I was confused about being asked for tracking - I no longer have it as I sent weeks ago, because it was successfully delivered to eBay who then shipped it to the buyer using the global shipping program. eBay international shipping shows it had been delivered and positive feedback left by the buyer.
I telephoned eBay who told me the buyer had been suspended (no feedback). I resubmitted the tracking number eBay provided, plus added that I'd used Royal Mail 2nd class.
I'm concerned that due to my lack of tracking to the eBay distribution centre in the UK, they're going to claim from me for the value mentioned in the case. Obviously the buyer has my item still.
Sorry, more waffle than intended. I'm a bit concerned, haven't come across anything like it in over 10 years.