The man is right. It's a big chain that buys on volume months ahead of time. They use central distribution points with seasonal shipments. They don't usually reorder these specialty things. It's big business... weather it's Walmart, Dicks or whatever.
SOLUTION: Support your local proshop. I'm sure the guy has broadheads that would have been more than adequate. Become a customer... tell him what you want. I guarantee the little guy will reorder what is selling.