To hide your caller ID, one goes to Setttings, Phone, Show my Caller ID. My phone shows it set to ON, and know way to change it. The phone will not let me use *67 prior to a number either. Please Help.
On my 3Gs I took those steps and when I clicked the "show my caller ID" button it took me to a page that took a second or 2 to load, then gave me the toggle to switch it off. Did you not get the toggle? I can switch it on and off.
I have a 3.0 phone and it will not let me toggle. My iphone is through work and maybe it is specially configured that way. Sure wish there was a work around. I even have the latest software from Apple.
I think that is your problem. Often times employers don't want their employees making anonymous calls to people, either within the company or out of it. I think you're stuck bud. You can check with At&t and see though.