Don't turn up when they are booked to come - unreliable.....

ADT installed a new alarm into my property at the end of August and it is now the 2nd of October and the system is still not working properly. I have had a technician booked twice to come and sort the problem and they didn't even turn up......(not even a call to say they can't make it). I expect a lot more from a large company like this - I have called the call center a number of times to now find out that I am booked in for the 8th of October for a technician to come back (if the even turn up at all). I have had a faulty system for nearly 6 weeks, which I am paying for and my property is not protected properly - ADT this is unacceptable