I ordered a couple of DVDs a couple of months ago, where only one turned up in the package and it was entirely feasible for the other to have fallen out. I managed to report it as "item missing" or "order incomplete" and they just shipped me another with minimal fuss. Having to go through the Amazon shopping app was a bit annoying, but the overall experience was pretty slick.
I canceled the return and looked at the Amazon app again. There is no option resembling "incomplete delivery" in my case. It looks like if you ordered only one item they assume you got something and they want it back before issuing a refund or replacement. I may just send back their defective envelope with its missing glue strip and hope for the best. I'll be dropping my Prime subscription at the end of the month.
