I had my 63 Riv painted in 2012 for $5K. Driver quality, but quite good. I delivered the car to the shop after complete disassembly, stripping, all rust repair complete, and in vari-prime. Up to that point, I had done all the work.
It was a time permits winter job for a local shop with a good reputation, I was encouraged to stop by every so often to see how things were going. Overall, it took 4 months. I did all the reassembly which took a lot of hours over the next couple of years. I suspect the shop didn't make any significant profit, but the owner is a car guy and takes on a few of these types of jobs.
You apppear to have a huge communication failure here. When I had my car done, I knew others who had used the shop, seen the work, and was very clear as to what I would get. I also invested a lot of hours (hundreds) into getting the car ready and finishing it after it was painted. I am still working on the interior, but it looks great going down the road.
Its a shame you are having a bad experience, but due diligence is critical in selecting a shop. Clear communication and expectations is equally critical.
Good luck, but there is no way I would have allowed this to go on for three years.