How private are conversations on Vodacom

I am writing this report out of concern about privacy of our conversations. My sister just told me that her boyfriend told her about all her conversations with some of her contacts, the guy knows everything that my sister thought it was private, my question is how come this guy have access to my sister's number.<br> <br> What I know is that, this guy used to work for Vodacom, so this means he's got some people in Vodacom helping him with this. What I know is that, even the police need some approval from their superior to be able to gain access to someone's account. Unfortunately with Vodacom, this can happen just like that.<br> <br> I have been with Vodacom ever since I can remember, but there are people who uses their powers to get into people's private conversations with ease here at Vodacom. I would also be worried if someone tell me that I have been speaking to so and so, about this and that, that is a proof enough that something is wrong.<br> <br> I am very very disappointed and hope that something can be done with this, maybe just to clarify some things and just to get to the bottom of this.