Calls my home 3 or 4 times a day.....harassment

I am on the no call list.  A recording calls my home 3 or 4 times a day. I do not want these services.  I have spoken to the man on the other end and ask that he stop calling, still I get the calls.
Can you tell me how to stop these calls.  I am on oxygen and have trouble getting to the phone.  
Please help.