You can't remove yourself from a robo call lit no matter what they say.
Just answering the phone tells them it is a viable reachable number,
and your number will be sold on a list to other robo callers.
Yes, it's common sense to not answer if you don't recognize the number. But when you have elderly parents living in other states, you can't always go by what number you recognize. Especially if they have Alzheimer's/dementia. That's why you check here! ^_^