I've seen the term pyramid snail used to refer to parasitic snails that attack things like clams, and to refer to Tectus genus snails (which are CUC snails). I don't think I've ever heard it used to refer to Trochus snails, so I have to agree that the store probably either got the name wrong or were offering you an alternative (though I have no idea how Tectus spp. compare to Trochus spp. for CUC purposes). As mentioned, there's no real way to know until the store gets them in for you to see.