It was a rather small shop but it wasn't really like a warehouse. They had a storefront and a shop area with lifts and tire machines and a storage area.
You said that you ordered 8-10 sets from them and only one set was missing an extra rim. There is a lot of shipping involved from NYC, to Cali, then overseas. If this is the only time you had an issue with an order, then I would really question the shipping first and foremost. But either way, the seller is ultimately responsible. I was always able to speak to someone on the phone and I didn't necessarily have to speak to the same exact person every time. You should be able to provide anyone with your order information for assistance. I don't even remember any names to be honest...