As a matter of fact now you are able to renew your "Refugee Protection Claimant Document", this wasn't the case in the past or maybe there was a lack of information with regards to the process. Anyways, there was an update on January 8th, 2019 by IRCC were they made the process of renewing the RPCD clearer. I quoted this from their website:
"Regardless of where the claim is originally made, clients should contact the nearest local Immigration, Refugees and Citizenship Canada (IRCC) office for the replacement or renewal of an RPCD. If the client does not know the location of the nearest local IRCC office, they may
check online."
And here is the link from IRCC's page (scroll to the bottom of the page):
https://www.canada.ca/en/immigratio...aims-general-requirements-administration.html
Good Luck!