DO NOT USE ADT AS AN ARMED RESPONSE SERVICE PROVIDER!!!
Had absolutely shockingly poor service from ADT when I still had an armed response account with them. 
Cancelled my contract due to them taking 45 minutes to respond to an alarm at my home, they wanted  me to pay a breach of contract fee which I fought. Was eventually contacted by an account manager who apologized profusely and emailed me with confirmation that my account is cancelled and all monthly and cancelation fees are waived. 

Now.... more than a year later, I receive an sms from attorneys that my account has been handed over to them due to non-payment. 
So I phone the number on the sms, the attorneys say someone will phone me back from the relevant department (also don't understand why they do not put the number of the correct department in the sms). 

So I phone ADT. was put on hold for 15 minutes and then hang up. Phone the emergency number, they put me through to the correct person. The "correct person" says she cannot view my account, she will ask the correct person to phone me back or I can phone the number I already phoned!! I cannot believe this level of incompetence, I do not understand how you are still in business. 

Now I have to sit and sort out my account that now has an impact on  my credit record because of your incompetence. Even though I am trying to sort it out, I cannot get through to anyone that can help.... I have to sit here and wait and hope the correct person phones me.  