Suggestions for getting company to return calls?

I have been having problems with the billing from a company. I've called, left messages and emails to the "finance manager" (if I call customer service they always forward me to this person's voice mail) I've tracked down her boss and the next level up also- VP of finance. I've been assured by them that the finance manager will get back to me that day...then they day goes by without the slightest acknowledgement. I've been told by a person in customer service (before being forward on to the land of being ignored) that they are getting calls with this same billing complaint. What can I do as my next step to get this resolved or to merely have them return my communication? I need new tactics here I think- any ideas would be so appreciated as I am at the end of my rope.

Have a friend of yours leave them a message that they want to make a large purchase from their corporation, and his or her name, then when they call back, he or she can give you the phone.

Come to think of it, even better, don't call, don't email, only converse with them by mail, and ALWAYS DISPUTE the bill. Keeping it in dispute puts the ball in their park, they must now contact you to dispute the dispute.

In other words, you say, "I don't owe this", they say "Yes you do", you say "No I don't", and around it goes.

Most companies will contact you right away, as a debt in dispute usually cannot be collected or sold to a collection agency. They want to get it out of dispute as fast as possible.