I know it's painful, and I do sympathize, but you don't appear to have a legitimate complaint. The bill is in accordance with the contract you signed.
You could try the negotiation option described in a previous post here, but if that fails you'll either have to pay up or damage your credit.
You can pay up, regard it as a lesson learned, and let go of the issue, freeing yourself to devote your energy to more interesting and rewarding activities. This option will also give you a feeling of some control (because you closed the issue yourself).
Or you can fight it, inflicting a huge emotional toll on yourself, and probably lose anyway. The frustration, anger, and feeling of powerlessness will damage your spirit and take up a lot of time that you could have been spending on happier and more productive activities. You'll also be casting yourself in the role of helpless victim.
This lesson, though painful, may save you from a much more expensive lesson in the future--I'll bet you'll become an extremely proficient reader of contracts!
I read contracts and I totally understand that I made a mistake. But you would think that a huge corporation would like to please its customers--apparently not.
I am just going to pay the bill and deal with it.
Maybe Walmart will get into the cell phone industry. They would not treat a customer this way.