They haven't been refuted, you just keep asserting a definition of a voluntary 'state' that does not, nor has never, existed. You're redefining the word 'state' to suit your ends of claiming it as a potential voluntary institution.
To make this claim, please deconstruct this post, point for point:
It might be best to break down some of the common attributes of a state. By most accounts, a state can have some, or all of the following:
+ An executive or executive committee of some kind.
+ A system to create laws.
+ A system to catch / stop law breakers.
+ A court/justice/jail system to deal with law breakers.
Let me know if there is anything that should be added. What is important however is that all of these are sovereign, and not within the domain of another entity.
So the question is, can these things be mutually agreed upon by consent outside the context of another state? I say yes, based on the possibility of if someone laid claim to an unclaimed area, and then others did the same next to them, then they could voluntary agree to these terms, and they could call it a "state". Why could they not self organize? Why could they not call this a "state"?
I am proposing that this is a logic proof that a state can be voluntary. If you disagree, show that it is not possible for this to happen.
Further, if you ask someone in the general public if they want to have the above listed attributed you will get many affirmative responses. This is similar to people saying "I don't want anarchy", "there needs to be some law and order" -- these are statements people make indicating their constant to the attributes of a state, and ultimately, is part of their definition.
With this, I am proposing that a good part of the general public is willing to consent to a state, thus making it being voluntary a possibility.
I would further note, that people can define things how they wish, and if the general public wants to say that a state can be voluntary then so be it- that is their free choice. If anarchists/anti-statists want to define that a state must have involuntary elements to it, then that is their choice. The problem however is that if they use their language within the general population it will cause confusion because of the differences. Worse, it can be viewed in a negative light because by saying that you are "anti-state", to them it can mean that you are trying to prevent them from a voluntary association with a state, or an entity that has the above listed attributes.
I would further question any axiom that it is impossible for a state to be voluntary, and in some way must have some involuntary element to it. Why should it be necessary to have to include some involuntary element? Here's another example- we should agree that the USA is a state (in the broader sense). Say that everyone within the USA that did not voluntary agree to the state just disappeared, moved out, or whatever- thus only leaving people who agreed to the voluntary association with the USA, should it then no longer be considered a state? That doesn't make sense. As well, why can't one call it a state in the example of "if someone laid claim to an unclaimed area, and then others did the same next to them, then they could voluntary agree to terms of their choice." Would they have to force one person into involuntary association with it to rightfully call it a state? This just doesn't make sense either.
Don't get me wrong, this isn't cheerleading for tyranny, it's a matter of how you deal with the general public and on how you work towards solutions to the problems. If you talk with terms of being anti-state then you can become an enemy since you can be seen as making others vulnerable because you are perceived as wanting to deny them the ability to self-organize a defense. Further, if you advocate for the abolishment of the state they are in, you are attacking something that doesn't necessarily need to be attacked-- but that doesn't mean you submit to tyranny either, one has to understand good and acceptable solutions and articulate them as to why the situation is not just.