Napa items can be returned back to their distribution center by a jobber or company owned store unless they went and purchased outside 3rd party. Talk to the store mgr. There might be a handling charge for the extra work and time they might need to sit on them before they can be "classed out". If you got them in Zachary, the store owner is Greg and a real nice guy. (tell him Juan says hello) It will also help to reorder the correct parts or use the credit for other items instead of a refund.
If they were purchased in Baton Rouge, those are company owned stores. They are pretty much obligated to "customer service" and give you a no hassle refund.
Option Z, wait till Jeff get back as he probably has buckets of thimbles and nuts in his yard.