In the listing from which you made your purchase, you should have seen an estimated delivery date.
Has that date passed already? Seems like the earliest it could have been mailed would have been yesterday morning. What are you messaging the seller about? Did you know there is no requirement that the seller respond? Did you know that you cannot open an item not received case until/unless the item is at least one day late? Have you read eBay's Money Back Guarantee?