I would have to assume that you inadvertently made a purchase from a US seller who listed using the Global Shipping program. Was the second charge to Pitney Bowes? They collect import fees upfront. If you were logged into ebay.com to complete your purchase, you may not have seen this but sellers who use the GSP are easy to filter from search results if you simply avoid listings with the subtitle 'Customs services and international tracking provided' when viewed on a desktop in 'list view' form on ebay.ca.
When you check the listing on ebay.ca, does it say, "No additional import charges at delivery!
This item will be shipped through the Global Shipping Program and includes international tracking."