If the last estimated delivery date was November 28, 2021, you, the buyer, can open an item not received case on November 29, 2021 (today). However, given the current situation with US mail as well as with some other carriers, my recommendation would be to give it a few more days. You have 30 days past the last estimated delivery date to open an item not received case.
After you open that case, if you have no response from the seller, you can return to that case 96 hours later and ask eBay to step in so you can be refunded.
PS: You have been here since 2007. If this is the first incident you've ever had of not receiving your purchase, congratulations.
