I agree with SlyOldDog and Rodney on this. That is how its done.
If the Admin contact is being "unhelpful" and without the facts who knows what sort of gripe he has with the company owning the URL - they may owe him money, or whatever. Then do as suggested, contact the Registrar concerned with proof that they are the owner.
It will take longer than if the Adin contact were helpful, but will be much quicker than messing round with the Admin contact if they are being unhelpful