I placed an order on the 20th that supposedly shipped on the 22nd, but it's been more than ten days and the tracking information (LT104012421CN) doesn't indicate they actually sent something. Since then the item in question as been listed as unavailable by the merchant, and upon noticing this I reached out to them and asked about the status of my shipment. They responded only that the item was in stock, they were sorry my item hadn't arrived yet, and that if I didn't receive it they'd issue me a refund.

This is a well-rated seller, so it seems silly they'd risk reputation over an inexpensive item. Should I wait another 10 - 12 days (closer to when my protection window runs out) to see if it does arrive, or file a dispute now since my order seems lost in the ether?

2. I suspect seller took orders but did not have enough articles to send out to buyer's, so some buyer's like you are not getting the article because there is no more in the inventory. When will they receive some more of those article, your guess is good as mine.

This seems very likely, since I was the first (and apparently only) person to order this particular item from their inventory. I decided to file a dispute as you suggested. Thank you!