Hello 'sincosound',
A seller is allowed to end a listing early. Sometimes something happens, - like the item breaks. Or maybe a seller noticed damage that she didn't see when she first listed it.
Now I knooooww what you're thinking, - the seller ended it early because the auction price was not going high enough. You can be sure that happens often, indeed, but nothing you can do about it. You cannot 'prove' it wasn't a genuine problem. You can always watch to see if the item is relisted at a higher price. But a seller is within her right to cancel bids and end the listing early.
If, after you've won the auction for that price, and the seller cancels the sale telling you he won't sell for so little, - now that is something he ought not to do. You can't force a seller to ship it, but you can express your displeasure in feedback if you are so inclined.
Have a look at the link provided by 'hereiam', - it shows all the acceptable times for ending a listing early. Mistakes happen. 🙂
