Sales calls and the do not call list

Isn't there a law that if you request to be put on a do not call list, that they must remove you? I have ADT calling me constantly about upgrading my alarm system, but I don't even use ADT anymore. I've been asked to be removed from their call list 5 times to the point that I can recite the BS they are going to tell me about how they are going to get their manager involved to make sure it gets taken off.

I've even gotten certified mail that left a note on my door saying I had to pick it up from the post office. I was waiting on something important, so I drove to the post office just to find out it was a letter from ADT telling me I needed to update my system

So is there anything I can actually do? It's not that big of a deal to hang up, but it's the principle of the thing. I've been called no less than 20 times, and most times I just hung up. But I've specifically asked them to take me off the list at least 5 times, and even stayed on the line to tell them that I've been told all of this before, and it didn't work, so they need to do something different. I'm getting pissed, but don't know what I can actually do about it