Whilst both parties may have contravened PP T&C's with the result that they may wash their hands of the transaction, it has to be said that if one party has paid money in good faith, and the other has failed to dispatch the goods, then it should be very obvious to them who is really at fault. It should not be too difficult for them to make a chargeback to demonstrate that failure to dispatch goods is simply not acceptable....on the other hand they may not wish to be seen to be condoning airgun sales.