Before Goldhawk & your MP try this....
http://www.ombudsman.postescanadapost.ca/
I have no idea of the actual policies in this situation but not getting your Registration fee returned seems like a real burn to me.
One thing you might investigate for the future is third-party insurance, DSI.com is one of several companies that offer insurance including types of items that the Post Office will not insure, they are also cheaper and apparently much easier to deal with if it comes to a claim.
I'm afraid my experiences with Registered mail (incoming to Canada) have not been good either. I've received many cash payments in the mail, the ONLY ones that have ever gone missing were sent registered.

"What else could I do? I had no trade so I became a peddler" - Lazarus Greenberg 1915
- answering Trolls is voluntary, my policy is not to participate.

"What else could I do? I had no trade so I became a peddler" - Lazarus Greenberg 1915
- answering Trolls is voluntary, my policy is not to participate.