You didnt get the right strain. They are most likely regular cherry shrimp. PFR are more intense red in color rather than pinkish. Pictures would help however your description sounds like regular cherries to me.
Yeah they're the same species, just the 'Fire Reds' have been selectively bred for a redder colorHere's a picture I managed to catch today. They seem the same as the red cherries (same size, very similar colour except a bit less vibrant, more salmony/pink), I have no idea why they had a different label (Red Fire Shrimp) or why they were half the price. I'm planning on getting some more tomorrow though!