Very bad service and responce

I had 5 times when my alarm went off, and when I tested my alarm, as per ADTs instruction, where it took 3 minutes and more for ADT to call me. I was told by the call centre agent that they were experiencing load shedding, and that is why the call took long. Your house it at risk when ADT's area is experiencing load shedding, is the message I got. I called ADT at the end of July 2015 in order to find out what is needed for me to cancel my contract with them. The ADT representative instructed me that they are loading the cancellation, the call will suffice, the service is to be cancelled end August 2015, month notice. I then called again after signing the contract with the new security company as a courtesy, because I stopped the debit order for ADT on my bank account. I was then instructed that the cancellation is confirmed, I just need to send a confirmation letter. I did so, and now get a call today that my contract will only be cancelled end of September 2015, I was late to cancel the contract in writing. I asked end July what was needed to cancel, and were never instructed to send a letter then. 3 other ex ADT customers complained of the same problem when they cancelled.