unacceptable service

I have an account with ADT since last year my account goes off on debt order every month. I get sms's stating that I am being handed over. Being a responsible person I call and follow up. I called the first time everyone that deals with accounts was on lunch. I got a promise someone will call back. Called again no one can assist or understand my query. I called this am I speak to someone I get td I owe R546. I have debit order how can I be arrears after a year. No one calls me back to clarify. I am extremely irritated and upset. I want to cancel my subscription ad soon as possible. How can I trust u with Mt security needs if u can manage my account? ?? I would like my account sorted out !!! I demand I letter with an explanation once this is done I want to cancel my subscription. I will go to a smaller company in my area