Still deducting after contract was cancelled

I have been trying since 30/06/2017 to cancel my contract with Cartrack. After sending numerous instructions for cancellation to the Customer Services email address, I was eventually contacted by a employee in their accounts department, who wanted to collect outstanding fees, who I then advised that I have cancelled my contract. Yet for some reason Cartrack still attempts to deduct random amounts on random dates. On the 12 of October 2017 I received a request from their Accounts department asking me to authorise a debit order of R 318.60, and I responded that this debit order is NOT authorised and that NO deduction of any sort may be made from may bank account. I also asked for an explanation of what exactly this amount entails and I also requested a copy of my contract which specifies the cancellation terms and conditions. No response was received, yet on the 25/11 a amount of R 237.50 was deducted. I have been a client for many years and paid a huge amount (compared to other tracking companies) for very little service, and now it takes me months and a lot of effort to cancel this contract. I will never recommend Cartrack to anybody!