You can enforce the contract and foreclose on them and take back the property. Or they can reaffirm the debt to you. The best approach at this point is if the contract is secured by the property itself, contact the trustee and see if you can move to exempt this from the automatic stay provisions in bankruptcy if the item is still pending and not fully completed. If the discharge has already occurred and the case is closed as per the trustee's indication to you, then you need to simply forclose and enforce your contract.