It depends on where you live. Your work has no value without customers, though. You won't be able to just deploy it as a SaaS and watch the money roll in. If

It depends on where you live. Your work has no value without customers, though. You won't be able to just deploy it as a SaaS and watch the money roll in. If you had a contract, take him to small claims court. It should be a slam dunk. Otherwise write it off and remember to have a good contract in the future (and maybe even escrow).