ADT says I must pay R671

Tuesday the 28th April 2015 at about 13h15 Ive received a call from ADT customer complains department in johannesburg asking me about my matter after explaining to the caller he said that he can see from the system that my contract was cancelled last year and I am not the J Msiza that is owing the oustanding amount the was a mistake he said he will call me back after theyve rectified it with the accounts department after about 20 minutes he called me back and said he could not get hold of the acooubts department but he will call me back as soon as the matter has been resolved today again I get the sms telling me that i must pay to avoid being blacklisted really I dont understand it happened when they broke into my house struggle to get an answer as two what went wrong I mean the caller from ADT he even said that he can see from the system that its their mistake I even asked him whats going to happen because my name has already been send for blacklisting he said i must not worry that they can reverse it but today I get sms saying I must pay as this the final reminder.Does ADT have different systems which make this confussion and frustration? ADT please sort your system