Knowing what state you live in might make for more people in the know to give you more info.
Iknow in Illinois ,roofers,plumbers, electrictions,heating-cooling, must be liensed.But there are ways to get around every law and a lot of "Home Improvement-Handyman"scams are run this way.
Any "Joe"with a hammer and a van can call themselves Contractor but that does not make them a Business.Kind of like buying a watch off the guy on the street.As soon as he has his money he is GONE!
Anyone in the trades who is self-employed and has a state license and insurance is in buisness to make a living and BUILD a business.Not only to meet State and local requiements do they get licensed,but to show the consumer that they stand behind their work,and want your business again and your referrals.
Any Pro on this site will tell you,always check for licensed,insured,bonded contractors with references,before you start any project.
Looks to me like Smallclaims Court and someone else to finish the job.Luck