Very annoying.
The Dispute can be handled in the first instance by providing the tracking number showing that it has been shipped or even delivered, for a Not Received claim and by demanding the return of the disputed item in the case of a Not As Described claim.
Even if you have a No Returns policy, you are allowed to demand the return before refunding, although you may have to provide return shipping.
The demand usually ends the claim, because that kind of scammer wants to keep the item. Having a No Returns policy encourages this behaviour, because the scammer knows that No Returns does not mean No Refunds.
The Unpaid problem can be lessened by setting up your Sell Your Item form to automatically cancel Unpaids after four days. I believe this also automatically relists the item. Still a four day delay, but no labour involved.
