Make a copy of the contract and highlight the information where you can take the pup back and wright a letter stating due to the phone calls and lack of contact on such and such days you are enforcing that part of your contract. Send it certified and also state that if the pup is not returned you will press charges and or take them to court. Also state that if any injuries are present or the dog is sick due to being poorly treated they are responsible for all vet bills. (May need added to any future contracts)
Also call the police back because he is your "property" till he is signed over free and clear and see what they are willing to do.
Also call the police back because he is your "property" till he is signed over free and clear and see what they are willing to do.