Peugeot Salt/Pepper Grinder - Interchangeable?

My local Williams-Sonoma is closing and everything in the store is currently 40% off. I was in the tiny and crowded store and picked up a peppermill…however, in my rush to get out of the store, I didn’t realize that I had actually purchased a salt mill instead of a peppermill.
Is there a material difference between the two? Or do I have to go back to the store to make an exchange…hoping that there’s product left to make an exchange.

Pepper mill’s case-hardened-steel mechanism cracks peppercorns before grinding for an even grind and rich aroma. Salt mill’s stainless-steel grinding mechanism is engineered to resist corrosion.