ADT/Londoloza Robbing us instead of Protecting us

Three years ago, I signed a contract with Londoloza to install an alarm system in my house and the contract came to an end in July. The arrangement was that I pay R300 for the alarm system and another R300 for the alarm response. A year ago, Londoloza merged with ADT and now called ADT Fidelity thus my account was transferred to this new merger. I have been sending emails and making calls to ask them to only charge for the alarm response starting from August with no joy. They have made two deductions for August and September without my approval and they are failing to understand that there is no way that an alarm response could have cost R600 in 2016. I am so disgruntled and unhappy with their bad attitude and services.