What's the easiest way to disable the voicemail on my cell phone?

I have an LG Banter through U.S. Cellular. Not the touch screen one, the older model. I would prefer not having to contact U.S. Cellular, but to be able to disable the voicemail on my own. What is the easiest way to disable the voicemail on my phone? (So that when people call, they won't have the option of leaving me a verbal message)