Buyer drops off the face of the earth seller cancels and buyer won't respond

Hi I'm opening a new escrow and the last buyer disappeared and did not reply to escrows request to sign the paperwork and release the deposit back to the buyer, now they are causing damage to the seller as we have a much better situation and this party who failed to make any reasonable attempt to honor their contract ,now won't even reply to get their funds back, no contingencies were signed off and they never did anything they needed to do in order to make any attempt to perform at all