request for line transfer still pending

My mother had requested a line transfer in august. This has been postponed by telkom and no agent was sent out to her residence. The call centre cannot give an answer as to why. All they can do is forward your query to the back office who never get back to you. The last system generated message received informed my mother that the installation would occur 27november. Today, 30 november, a gentleman arrives in an unmarked bakkie, with no indication that he works for telkom. He also has no verification Id or documentation. How a would a client know that he is a legitimate agent for telkom? My mother has now been living in her new residence for 2 months with no landlines and yet she is still being billed for her telephone. Can a manager please contact her or sort this out.