There is no duty on items valued under $20 CDN (about $18 USD). There is no sales tax on items valued under $20 CDN either.
The item was purchased from a seller who uses the Global Shipping Program on items valued under $50 against the advice of eBay.
On the other hand, many US sellers claim to have been signed up for the program without their knowledge.
File an Item Not Received dispute. You paid and did not get your money back. If you had done this in the first place, you would have been reimbursed in full. The seller did not have to be involved.