Yeah once the stamp has been issued you can't get your money back. Only way you could get the money back is if you canceled the application before it was approved.
I briefly remember the problems you had something about the noveske lower being out of spec? If I were you I would probably see about getting it brought back into spec. If Noveske won't fix it publicly shaming them may get them to move. There has to be a way to fix it. The problem you may have with trying to sell it to a dealer is that there would be another 200 tax and form 4 that would have to be filled out.
Once a lower receiver is registered as a SBR (I'm assuming that's what you did), it's always a SBR. It will always require a tax stamp to transfer to another individual and the appropriate paperwork to transfer to a gunsmith or manufacturer for repair.