Go here:
http://resolutioncenter.ebay.ca/
and start an Item Not Recieved claim..
The seller sub-contracted shipping to USPS who delivered the item to Pitney Bowes in Kentucky who processed the duty and taxes and added a small handling charge.
Pitney Bowes then subcontracted shipping to CANPAR, who in theory will deliver it to you.
None of which is relevant to you. Just open the Item Not Recieved claim.
If none of the subcontracting shippers can show delivery, then you will be refunded. There may be a short delay in getting the duty and sales tax component back, but it will happen.
Don't overthink this. The tracking numbers are for the benefit of the shippers and Paypal. They also protect the seller against scammers who claim non-delivery. None of which is useful to you.
Just file the claim and get your money back. All you have to say is "I haven't recieved my item." Easy.