Trouble setting up a moble hot spot on my Iphone 4s.

I seem to be having much difficulty setting up a Mobile hotspot on my IPhone 4s. I go to settings, General, Network, then click on "personal Hotspot". Unfortunately, ever time I do so, a screen pops up that says the following: "Set Up Personal Hotspot" To enable Personal Hotspot on this account, contact Version at 661 or visit http://www.verisonwireless.com/b2c/index.html" I have tried calling and visiting the website, and I am extremely confused. Please point me in the right direction, and you will be greatly appreciated.