Parts being returned for store credit isn't a big deal IMO - it makes sense for the company to do that, because it keeps you shopping with them. Once you have some store credit built up, you buy your next order with them, when you return other parts, those become store credit, it ends up functioning the same you just have some "credit" with the company

I just contacted FCP via live chat (literally open on my other window right now) for an order that was missing a part, and I was hoping to get some extra parts I missed on the order sent expedited with the missing part. They can't combine a "regular" order with a missing order shipment, but they expedited the part that was missing and then refunded me the cost for expedited shipping on the other parts.

I have always had a really positive experience with FCP...