Failure to supply as listed

[moobooinc]

I purchased an item and paid via paypal $9.95. The item remained undelivered for almost 3 weeks (and counting). I contacted the seller who indicated that a replacement would be sent and a follow up with the postal service would be undertaken. I was shocked by this last statement as this seller is a major stockist and long time eBay user and would know that standard surface post in Australia is not traceable. My concerns were added to when I looked at the item I had purchased to find it had been relisted several hours after my tranaction with a buy it now price of $99.95 and several items in stock. I contacted the seller again and was offerred alternative items (of no use to me or a refund). Can anyone advise if the seller having sufficiewnt stock of an identical (the same item) is obligated to supply on the purchase I made and at the price and conditions at the time I made the purchase. I at no time was aware or even advised that the sale price was not accurate. It is only by my own research that I note stock availability and increased listed price. The seller has not made any mention of this item other than to indicate no stock to honour my purchase. HELP