Is $7,000 to redo a bathroom (labor only) a fair price?

I recently had my bathroom redone by a referral of a friend of mine. I was charged 7k for labor costs only. There were some key critical errors that I did not like, one being the plumbing work to my bidet toilet was done incorrectly, causing the toilet to leak water from the bottom when flushed, and the pipes of the toilet were also leaking. I brought it up to his attention, but he did not want to fix them and was very stubborn. My wife accidentally handed him the payment in full via a check before I noticed these errors, but I was able to successfully cancel the check. I mentioned I would gladly make a new check once the mistakes were fixed, but he refused. At that point, I asked him for his contractor's license number, and he told me he was not a licensed contractor. My mistake was not asking him if he was licensed before he started the job. Yesterday morning, I was served a small claims document, as he is suing me for cancelling his 7k check. I am questioning if he has any grounds to sue me if he is not a licensed contractor.