I had a similar problem with CRS calling me when the person who they were looking for no longer lived here. They didn't beleive me and kept calling and being EXTREMELY rude. Of course I tapped 2 of their calls, and when I couldn't call them back anymore due to full voice mailbox, I ended up calling the Nova Scotia government because the calls were originating from a 902 area code. It was the best move I ever made. I filled out a form online, and submitted it. About 3 days later, the NS Government called me and sent CRS in Mississauga a letter of complaint and gave them 10 days to reply. I'm still waiting for the reply, but I got more amo than ever now to take these bastards to court. If they call again and harrass me, it's off to a lawyer I go for damages.
If they are calling you from a 902 area code, you can call the Nova Scotia Government at 902-424-0414 and inquire how you submit your complaint.
You do have rights, and it's best you understand the collection law.