House alarm was paid for!

Three years ago when I moved into my house I arranged for ADT to install an alarm system for me. I was very emphatic at the time that I wanted to buy the alarm and not rent it. I paid ADT Alarms R2938.00 for the alarm and have been paying a monthly radio monitoring fee of around R450 per month ever since. <br> As the complex that I live in has since up graded it's security with ADT guards manning the gates 24/7 and mobile patrols through out the complex 24/7 I did not see the need for the radio monitoring any more so I gave 30 days notice of cancellation for the radio monitoring. I then received an email from ADT informing me that they will be contacting me soon to remove the radio AND the alarm system as it is a rental alarm! I sent ADT the tax invoice they gave me after paying the R2938.00 three years ago and they rep**** that this was for the installation of the alarm, even though the invoice details control panel, passives, etc and the of price each. I now have had no response from ADT regarding this matter and I contend that the alarm is mine as I was told that at the time three years ago. Nowhere on the paperwork I have does it state \rental agreement\"!"