Bought something on eBay (Buy It Now) but several days later, seller then tells me she doesn't have that size after all. Fast forward another couple of weeks and I get an eBay message saying the seller wants to "cancel the transaction" and if I don't reply it will automatically be cancelled anyway. I understand they get their fees refunded if the transaction is cancelled in this way.
Should I accept the cancellation? I don't really see why they should get their fees back as they were wasting my time by selling something which wasn't really available. However what happens if I don't agree to cancel the transaction? Am I then liable to buy something which isn't available? 