This is a member to member board.
If you give us the transaction number of your purchase (It's on the listing) we can look at it for signs that the seller may be unreliable.
We would also need the date of purchase and the date your payment cleared, to calculate when it is likely to arrive.
Generally, if it is coming from Europe by Air it would take about 15 days.
From North America 15 to 20 day.
From Asia 30 days by Air.
You can file an Item Not Recieved dispute with eBay. Do not let this go longer than 40 days from purchase. The Resolution Centre is at the upper right corner of this page under Customer Support.
You can post more exact information. There is even a way to get a refund if more than 45 days have passed,but working with eBay is easiest and fastest.