A while back, the same thing happened to me. Seller put chip in a "half" vinyl holder with a single piece of tape over the open end and left it loose in a #10 envelope. I received a lovely half vinyl holder but nothing else. Corner of envelope was blown out. I checked my mailbox and called the local PO but they didn't have it. Seller says "I've sold [insert large number] of chips and this has never happened to me, ever". He didn't have another of the same chip, but after a week or so, he had another one that was similar in value, so he agreed to send it to me to clear the books. All's well that ends well (in my case). Good luck!