The title showed me several choices, about half from the USA and half from China.
Oddly the Chinese ones seemed to be more expensive.
The US sellers, properly, used the Global Shipping Program.
In any case.
How long has it been since your ordered?
I would allow 20 days for delivery from the USA perhaps a little longer due to the holidays when all the shippers are over whelmed and understaffed. Say 20 business days. (No weekends and no holidays)
Allow 30 days from China. But they don't celebrate Christmas or the Western New Year, so 30 calendar days.
First contact the seller.
This link in on the listing, at the right.
Ask him for the date of shipping, the service used and the tracking number.
If you do not get a satisfactory answer*, immediately go to the Resolution Centre at the bottom of this page and open an Item Not Received Dispute.
The first step is to contact the seller. You already did that. Escalate to a Claim.
If the seller cannot prove delivery (that tracking number protects him, not you), you will be refunded*. If not by the seller, by eBay.
NOW
GLITCHES and IMPORTANT POINTS
If the US seller used the Global Shipping Program, say so in the Claim. Items are often repacked at the GSP plant in Kentucky** and sometimes misdirected.
On the slightly brighter side, if you are refunded by the GSP and the item later shows up, you can keep it. They don't want it.
And again, Chinese sellers often say they will send a replacement. They won't.
If too much time has passed since your purchase, eBay may not entertain your Claim.
Go instead to Paypal. The Resolution Centre is on the left side of your account page.
The system is pretty much the same but you have a full 180 days (six months) to make your claim.
But start with eBay.
And if the worse comes to worst, you can also try a chargeback on the credit card I hope you back your PP account with.
* An offer from China to send a replacement will be a scam. You want your money back. Only.
** It's a long story.
