I have now received a message from the buyer saying:

"As I said I would not have bid at all if I had been told it was not Australian stock.You call My camera focus and ask him if it is if you think I'm mistaken.I now am at the stage of wanting a partial 150.00 refund.If you don't agree I will file a item not as described case and leave appropriate feedback."

What should I do now?  I didn't misrepresent he item (see my items descritpion above) . . He never NEVER asked me if it was AUSTRALIAN STOCK . . . he asked me if I had the receipt.  That is the ONLY question that he asked me prior to bidding 11 seconds before the auction ended.   Unfact no one asked me if it was Australian stock.  They asked me about the receipt and if was damaged etc. .   My description is described exactly as it is. 

Sorry about this peeps. . your further guidance in this would be really appreciated!!