ADT FEDILTY *******

Please can someone please help with how i can get something done about these ADT *******. I have been trying to cancel my contract after they took over from National Security. I have sent emails and called numerous times. they just keep debiting my account. The staff are so rude it is disgusting that we have to put up with bad service in South Africa. I have now been told by my bank that the debit order can not be reversed as ADT have blocked it. Seriously this is my personal bank account and i have no say over it. I am sick and tired of this