phone line down since the 28 nov

My 79 year old granny's phone line has been down since the 28th of November, after several calls to the call centre nobody has been sent to repair the line. I asked to finally speak to a supervisor on the 4th of December and was told that he is busy and will return my call, however no call received. I advised the call centre the urgency of the matter as the elderly woman lives alone, they did advise us that the turn around time for a repair is 48hours, however it is way more than 48 hours and no response.