At the top of this page is a Search bar where you can enter the keywords for the item you are looking for.
Maybe some other seller has the part.
Or.
You could contact the manufacturer and ask him if he has parts or a Canadian dealer.
Or.
You could enquire at local machine shops looking for someone to custom make the part you need. This can be surprisingly inexpensive, especially if you put a value on your time.
Was the item you purchased supposed to have the part?
If so you have 30 days from delivery for an Item Not As Described dispute through eBay.
And you have 180 days from Payment for an INAD dispute through Paypal.
If you need advice on either one, let us know, by using Reply on your original post.