Dont trust the ADT guys

Towards the end of July there was a guy in my area promoting ADT so he came to my house and I told him I dont need an alarm and he said they are running a promotion which I will not pay for 3 months and if I am not satisfied I can cancel. At first their office called me to ask if they can deduct the annual fee i thought this is unfair to pay since I wont be that long but I left it, I called them on the 1st of November 2022 to cancel and the lady said she is going to ask someone to call me back she never did. I then see the debit order going off and I call to cancel coz I am not using the service at all I was told I am on the 36 months contract and the rep never told me that. I am so upset with myself for allowing him in my house and not reading the page he gave me coz he said its just for confirming the banking details for the once off fee. Now i was told I owe R3375 and I dont have that kind of money, am so angry