Buyer is a complete idiot. With that said, NEVER, I repeat NEVER, use FedEx or UPS when sending your rep to Canada. I realize we had a postal strike, so there wasn't much option, but the buyer should have just told you to wait until after the strike to send it.
Now back to why you should NEVER send a rep, or much else for that matter, using FedEx or UPS. They have their own internal customs departments and try to max out how much they can collect in duties from you. They also slap on their own internal customs "processing" fee. You are practically guaranteed that they will value your rep at 100% gen value for calculation of duties to be charged.
Canada Post, on the other hand, rarely will even open up your parcel if it is under $80 in value, and you probably will never get charged duties (I have yet to pay any, except once when the sender put a value of $300

). On the downside, CanPost can lose quite a few parcels, especially during internal management/union disputes .......