Exactly what I am thinking. Maybe the dealer knew something was up with the bow when he sold it to you and now is trying to save face? Maybe someone dry fired it before you bought it? Who know, the possibilites are endless.
I might even call Bowtech, and tell them what your shop owner is telling you. I am sure he might get an earful from them for telling you the limbs are only good for 3000 shots.
Either way, time for a new shop my friend