Communication requires two people to be willing to talk. If one of them just doesn't want to listen, just hear themselves talk, what can I do?
This includes them not listening to me telling them that I'm not willing to talk to them if they're not willing to listen (in more, or even fewer words than that).
There is no magic trick to make people do what you want them to do.
> me telling them that I'm not willing to talk to them if they're not willing to listen
Well, that attitude isn't going to fix any of your problems. Review the fine article; Heading 1, "Observations vs. evaluations". I might try ask them why what you are saying doesn't seem to provoke much of a response, but honestly you aren't going to get much joy out of an internet forum for solving communication problems.
I want to point out though that you propose "I might try ask them". I want to point out that that would get no response. That is the whole issue which I'm trying to find an "out" for.
Odds are pretty good that any problem is building up over a couple of conversations before it manifests, people are usually obviously walking into trouble, sometimes weeks before things get obviously bad. Often a presentation problem (always doing something that does a little damage but isn't important, like 'joking' insults or forcefully characterising the situation), sometimes an attitude problem (it is surprisingly easy to clearly perceive things that are not there, like the situation being extremely positive or negative - there are some unbelievable whingers out there), often an expectations problem (wanting something out of the conversation that just isn't going to be given, like firm commitment to a radical idea).
When I see people who can't get a straight answer, or when it happens to me and I reflect carefully with hindsight, usually it is an expectations problem that leads to other issues. It isn't much fun accepting to that sort of problem though, so bad luck it that fits you. On rare occasions, I've identified expectation problems and then just abandoned a relationship because I don't want to change.
One related addendum I make to the NVC framework is people make all decisions by copying other people who look successful. Expect no exceptions unless proven otherwise.
Otherwise, tell them that you find that the meetings aren't adding value since you've already exchanged all the info that can be communicated, and excuse yourself.
Have not tried it, but the NVC book says to keep empathizing (without agreeing) until they stop. I think it works for most people. But for the pathological folks who just ramble on and on and keep changing topics, the book actually has a phrase along the lines of "I'm having trouble connecting with you in this conversation. Would you please ...?" (I don't remember the phrase, but the request is to explain the purpose of the conversation). I have not tried it.
If your concern is they are not listening to you (i.e. you can talk but they don't process it), that's actually very normal. And the solution in the book is to empathize for a while, and then specifically point it out and request they reflect back what you have said to them. Now I can tell you from experience that this needs practice - most ways of saying it will trigger defenses.
Frustrating sometimes? Definitely. But it works.
A typical situation would be someone trying to deflect blame by ensuring they have talked to someone else before making a mistake, just so they won't take 100% of the fallout.
At the end (which will come eventually, especially if you only answer with yes and no, so there are no follow up possible) you suggest a great solution for some problem they mention, which you can do because a) you are detached and b) they talked a lot and you had ample time to figure things out...