Call, and let them know your not happy with the purchase. I'm sure they have a return policy. Or check out the receipt/ paper work they gave you.
Yes, they will replace them for no charge
As the previous has mentioned, just contact them and let them know your situation as I am sure they will replace them since it is no big deal to change lenses from it's frames.
I am not familiar with the optical department. Why not inform that department, about your problem. I'm sure they would be glad to help you.
No problem just bring them back
I'm not familiar with their optical department. Your best bet is to call the optical department and talk to them or go into the store. Or you could try looking at the Costco website to see if they have anything on their about their policy
Thanks! Your answer is awaiting moderation.