It might depend where you bought it, ie, from what country. If you bought from China it is not likely a real tracking number at all, just a shipment number to let you know it is on its way. If it is coming from China it could take months to get here because all the shipments from that country are being checked on arrival for illegal drugs.
Either way, on eBay you have 30 days after that LAST estimated delivery date to file a claim if it does not arrive.
And if you want to wait longer to see if it shows up, you have 180 days from when you PAID to file a claim on PayPal.
You didn't say where you bought it from, which is an important piece of information.