sounds like the LFS gave you a long tale to sell a fish. not saying you dont have a breeding pair but these generally are expensive and harder to come by. sounds like they are a "bonded pair" and not a "mated pair" which indicates a big price difference.
however if they do lay eggs though, leave them. if for some miracle they make it to adulthood ( sorry, they wont ) youll have baby clowns to sell, or trade. unfortunately i know they wont make it in a display tank ( food requirements, pumps, predators.. ) so i would still leave them as a natural food source. a healthy natural food.