It happens frequently on sought-after items. I email ebay from time to time and encourage you to do the same. They should simply remove the option to end auctions early.
BTW, if you can prove that you was the last highest bidder (via the emails that you receive from ebay) then you rightfully bought the item - at least in Germany. There have been several court decisions that confirm that the original terms of the offer (including ending date) are binding and that removing the item from the internet platform has no influence. The only back door to the seller is to argue that he found a hidden damage etc. and that he ended the auction because the description was invalid.
