All you can do is try to sue for the money, for breach of the contract. If the contract was with, or was guaranteed by, an individual person, you can sue that person; unfortunately, if the contract was with an LLC or corporation and that business is now defunct, you will not recover anything. (When the contract is with an LLC or corporation, you can only sue the business itself, so if the business goes out of business, there is no one to sue.) Even if the agreement was with an individual, if he or she lacks the income or assets to pay, or files bankruptcy, you are unlikely to recover money, too.