I suspect that they have Rogers cell phone list. Are you on Rogers?
I did not have this problem with Telus or Bell, but have had Debt Consolidation and other marketing type calls on my Rogers cellular.
There is a new Do Not Call list in Canada that may help. Don't know if it works for Cell phones, and may not work for calls originating outside Canada.
Saw the no. on my caller ID, but there was no name, so I didn't answer. Glad I didn't, because according to another people it's a Spanish recording, and I don't habla mucho Espanol!