I'm the one who just went through the sewing machine debacle. Definitely contact the BBB (if they are around), look for some reviews of this place on the internet, contact your attorney about the laws in your state and advice on how to handle this. Also email or write to the Attorney General in your state. I didn't respond to the shop owner immediately when they called me so he knew I was checking out what I could do.
I feel bad for you 'cause I know the horror of all this. Let your friends offer their machines - makes them and you feel like you are not alone.