You have already answered your own question.......Yank it and move on.
I had a similiar situation, except I did all my own metal fab, paid monies up front to my body & paint friend.......four long years later, excuse after excuse, I finaly got what I paid for.....sweet *** paint job....problem is once I got the car back I had all but lost all interest.......moved on to other things.
The car has sat now for 4 years 95% complete under a car cover in the corner of my shop, just lost interest.......Have considered more than once to just sell it and move on.