the incoming call numbers?

I have Sprint right now and pay extra for detailed billing and it only shows the outgoing call numbers, time etc and for incoming calls it only says "incoming where the number would be"

I called sprint and asked and they said its not possible to show the incomeing call numbers..........but they can trace them if i wanted lol

Someone else said that nextel shows the incoming numbers so you would think sprint would to.

I need this info because my work will pay for the calls if the call is about work........So what cell phone services show this info?