Statement of different contract terms

So last week i contacted ADT to cancel my armed response service as we are relocating. Mr Majola Mzwakhe informed me that i cannot cancel my subscription because i was under a two year contract. i informed him that the 3rd party that installed my alarm system explained to me that i can cancel after a certain period as long as the alarm system installed was paid up for. I then sent him the document i signed of the day of the installation where you can clearly see the option for a two year contract BUT it was never selected. i signed all documents of the day of installation confirming with the 3rd party installer that i am not signing a 2 year contract. i sent through the documentation to Mr Majola Mzwakhe whereby he advised that he will send the cancel request through to the cancellations department and someone will be in contact with me. since i sent through the documentation on the 3rd of September, and after two follow up calls with a lady telling me to be patient.... i am now still waiting for feedback from ADT regarding the cancellation.