That's crap! If their ad says it they should honor it. I hate them for crap like that and their prices also.
My exp with them is their gunsmith. When one day I asked how much it would be for them to pin on a flash hider to an AR 14.5" upper and they said they can't do that it's illegal. I said I would just be bringing in the upper and for it to be legal to put on my lower I would need the flash hider pinned. They said if you brought it in I would be bringing in an illegal item. I told them they should look into their info more, I can own a 10.5" upper if I wanted to as long as it wasn't a complete rifle if I didn't have my papers and left. Haven't been there since.
Next time just find a Gunsmith that is competent and familiar with the laws and regulations.
I know somebody
The most important thing to be learned from those who demand "Equality For All" is that all are not equal...
Gun Control - seeking a Hardware solution for a Software problem...