Keep calling even after I've told them to remove me from their call list

I have been getting calls from this number DAILY. When I connect to an actual person I am promptly hung up on when they ask how I'm doing and I reply "not good. You keep calling even after I've told you to take me off your call list". Twice they actually stayed on the line and said they would remove my number but it may take 24 hours. But this has been going on for weeks and I'm sick of it!! I'm already on the do not call list.