do you carry hersheys's dark chocolate miniatures

I bought a big bag last week

You should call them directly. This forum is more for map related questions.

I think I may have seen some of the big bars, but usually they are only in the variety packs, or the bags

I believe the miniatures only come in a variety pack (milk, almond, dark). If you call Costco they can tell you how much they have in stock.