I never answer but they keep on calling. Very annoying. What ever happened to the do not call list

They called 2x in a row today 5 mins apart. I blocked their number on my iphone. See that works for now. Under settings, phone blocked!

daily calls with nobody on the other end.

Already blocked on my Nokia Lumia 928

These people are driving me nuts.  They are calling my corporate provided cell phone.  This number out of Maine calls and no one is there and then about 10 minutes later i get a call from the pain meds people who all have East Indian accents.  When I tell them they are reaching a corporate number, they ALWAYS say "no, we are calling about your pain medication prescription".  AHH, I am ready to scream.  How can I get these jerks to stop.  I am on the "do not call" list but that isn't helping.