IPhone :: Personal Hotspot Unable To Activate For 4S Running IOS 5.1.1

I cannot get the personal hotspot to work. Even though I've confirmed with Verizon that it is turned on for the right hand set on the account, when I tried to turned it on on my iPhone it just prompts me to contact my carrier either via phone or website. I have an iPhone 4S running iOS 5.1.1 and I've tried the following:

1. resetting the network setting.

2. changing the phone's name to a single word without spaces nor special characters.

3. reset the whole phone.

4. combinations of the above several times.

These are supposed to be workable solutions based on what I've read online, but they didn't work for me. My online search kept leading me to an imaginary solution that states:Another way is to retype the access point name in. Go to Settings > General > Network > Cellular Data, scorell down and fill in an access point name under "Internet Tethering" for APN. I call it imaginary because I do not see this on my phone anywhere. Under network there's only the option to turn cellular data on or off, and under statistics there's a cellular data usage. I don't see "APN" or "Internet Tethering" anywhere.

Info:
iPhone 4S, iOS 5.1.1