Debiting from our account without permission

In 2010 we purchased a new vehicle and selected the option to have a Matrix Telematics unit fitted. What a nightmare!! Firstly they used to call me every morning as I crossed over Mahogany Ridge Road in Westmead because it was a dangerous area. I asked them to please note on their systems that this was my regular route to work and a phone call every morning wasn't necessary. Despite this nothing was done. Later that year I was in a terrible car accident and the car was written off. The bank was settled for the vehicle and a letter went out to Matrix to cancel the contract as the vehicle was no longer. Despite only having the vehicle 8 months I wasn't credited for the remainder of the contract which couldn't be used. Now some years later they have started debiting my account with fee's again WITHOUT MY PERMISSON. As I only transfer into this account to cover debit orders I authorise there isn't sufficient funds for this debit order and now they have resulted in 2 months worth of bounced debit order charges. R230.00. When they call they ask us to send another email cancelling this however they don't they try and debit again next month . . . THIS IS SHOCKING!