I live in Colorado. I hired an unlicensed contractor install flooring and baseboard/ trim in my basement 3 weeks ago. The flooring installation was complete. They were paid $2000. I found out the follow day jewelry was stolen by one of the workers, who eventually confessed. I stopped the project and fired them. A police report was filed. No baseboards installed. Now contractor is threatening to put a lien on my house because I owe him $1700. No written contract. Is this lien valid and how can I fight this?