I sympathize with your plight sir, but may I offer the thought that it (surmising) dang sure wasn't done to you intentionally. The fact of the matter (on this planet) is that;
Feces happens.
People get busy and behind.
People can be forgetful.
People are only human.
Falling behind can be the mark of a good workman cause everyone wants them to work for them. (right NOW)
Just because you contracted for a job with him doesn't mean the world started revolving around you.
With good gunsmiths, proposed delivery dates are (in my mind), proposed probabilities. (If the sky dont fall, heart attack dont come, wife dont feel neglected, workload dont bury them, etc.)
Its only money, some things are more important. I realize this may be hard to swallow when you are the one getting the short end of it but sometimes you gotta rise above petty frustration and be big about it.
George has done one job for me, custom built an extended mag tube for my sons 870 YE 20 ga., and it was late but good work. I didn't beat up on the guy for it being late. Just appreciated the completed good work. Every anxious phone call to him was met with respectful apologies and in no way did the guy ever leave me with the impression that he was a hack or crook or anything bad. A spirit of patience and understanding may not get your gun or money back as you wanted, but you'll feel better about it throughout the waiting process. Did you try saying a prayer for the man or just sit around cursing him?
Again, I DO sympathize with your situation. But lighten up on the man. There's obviously more to this than is known at this time.