Where is the seller?
If he is in the USA or Canada your item will take upwards of 20 days to arrive. Don't worry until then.
If he is in Europe it will take upwards of 15 day to arrive. Don't worry until then.
If he is in Asia it will take upwards of 30 days to arrive. Don't worry until then.
If those dates have passed, you have up to 45 days from purchase to file an Item Not Recieved Dispute. Normally we discourage these before Day 40, but in this case the seller is unresponsive.
Go ahead and file an INR after the reasonable wait.
The seller then has to show that the item has been received or you get a refund.
More likely the item will arrive while the Dispute is still open. The Post Office very rarely loses items.
I detest the demand for tracking. It does not benefit buyers but only causes confusion and concern. And adds to the cost of shipping. The purpose of tracking is to protect sellers against fake INR claims. There is no benefit to the buyer.