Extremely bad service

I have an unknown line rental on my Vodacom statement. I have been calling Vodacom every week and sometimes twice a week to get this issue resolved. As soon as I give the agent the number in question I told that the issue is being escalated or I am pushed and shoved to another department only to be told that they cannot help me. I am being billed for a line rental and a handset which I do not even have in my possession. I tired of being given the runaround and paying for something I don't even have