The latest CIRA policy is that any modification to the whois info for .ca domain names is visible only on the specific registrar WHOIS lookup.

Thus any contact details won't be visible on the global WHOIS search engines.

If you are a SiteGround customer and you wish to make changes to the WHOIS information for your domain, you would have to pay a $19.95 transfer fee. You can request this service by posting a ticket in the Billing category of your Help Desk.