The seller may have been confused by your response, especially if he is not used to dealing with customers for whom English is a second language.
Try this :
I am in Canada. Please send me an invoice with the shipping to Canada by First Class International. You will be pleased to know that USPS now includes Delivery Confirmation on this service.
If you cannot ship to Canada, please send me a Mutual Cancellation, which I will agree to immediately.
If he sends the request, do agree immediately. This will end any threat of an Unpaid Item Dispute. Both of you can leave feedback. You should leave either no feedback or positive saying "Thank you for clearing up the problem."
But.
The problem started when you bid on an item that is only available to customers in the United States. The next time you see an item that is not available to Canada, BEFORE BIDDING, ask the seller if he will ship to Canada and for a firm quote on the cost of shipping.