ADT Technical - useless as always !

Recently we had to have our CCTV system repaired; one of the cameras wasn't working. The ADT technician managed to drop the camera from height of +-2 meters while fixing the cabling, but he reinstalled it as it still worked. A week later the camera failed. With great difficulty I managed to contact him via the ADT call centre; he said he would check camera availability and let me know what it would cost. After a week and more than 6 calls/emails to ADT Technical, I'm no wiser and we still don't have any clue as to what it will cost and when we can get it. Calls get cut off, emails go unanswered, and our security is compromised. Why don’t ADT actually provide some service instead of us constantly messaging how important it is to ensure our security ?