and another 29.79 at the door
This charge won't be covered by the eBay Resolution Centre btw.
It is probably made up of Canadian duty and sales taxes plus the courier's customs brokerage fee.
The customs brokerage will NOT be returned by anyone. And that is probably the first $20+ of the charge.
You can get the duty and sales tax part back from CBSA by using the phone number on the back of the invoice the courier gave you.
You will also be required to return the unwanted parts to the sender if he demands them. While he is supposed to pay for the return shipping, internationally this is difficult to impossible.
You both need a lot of trust, so keep your communications polite.
Remember to mark the returned items as 'Returned Merchandise', so he doesn't have to pay duty on the returns, which will not make him more cooperative.
Politely.-- Captain Malcolm Reynolds.