You can find all of the information on our privacy option for your homephone here: http://support.videotron.com/residential/telephony/optional-features/privacy
We offer also option for anonymous call rejections: http://support.videotron.com/residential/telephony/optional-features/anonymous-call-rejection-77
And just straight up phone number blocking: http://support.videotron.com/residential/telephony/optional-features/phone-number-blocking-60
All of these options should help you avoid this kind of unwanted calls.
Your Community Manager