The no call list is not very effective. Large and/or reputable companies comply, usually, but most of the places that you would want the list to apply to just don't care.
Online Canadian pharmacy have been calling me from various numbers including from this number for the past 7 years and harassing me.What should I do. I have been upset and told them so many times not to call me. Again they call from new number.
For a land line you can buy a call blocker - a piece of electronics that plugs into the phone line between your land line phone and the wall. It also plugs into an electric outlet. You program it with the numbers you want it to block.
Many smart phones come with a call blocking app or you can download one. Again, you program it with the numbers you want it to block.
For a simple cell phone ask your carrier. Or put the pest in your contacts list and assign them the ring tone "no ring" or "silence". That won't stop the calls but it will make them easy to ignore. You'll have to empty your voicemail occasionally.