I haven't had an issue with my orders through Treestuff at all. I am a professional and I research the products I buy long before a purchase. I learned long ago, that people on the other end of the line probably aren't as knowledgable as me about what I'm ordering. Missing items, I'd be miffed, but a rivet? Use a screw, it will make replacement that much easier next time.
Here's something to ponder. That FatBike I bought last summer had a recall on the front forks. I bought this from one of the largest and best known dealers on the Eastcoast. It took them three weeks to send me a new set of forks. They arrived in the wrong color. Another ten days passed before I got the right fork. This was a safety recall! After I contacted the manufacturer, they said it should have been handled within three days. I got no extras or even a sorry from the dealer.
I think Treestuff is doing the right thing.