debiting incorrect amount and not taking ownership . they do not have complains department to resolve your issue

cartrack called me in November 2016 for promotion ( R 199.00) service/ device tracker and original amount was R 317.00 however they debited R 317.00 first installment instead of R 199.00 then I reversed the amount . I called to ask them to rectify and I have been speaking to different consultants since eventually they listened to my call when the application was done hence the recording proved that it was their fault . in June 2017 they asked me to pay 372.00 and they will resolve it , 3 days after payment they called me (different consultant ) asking me to pay for the past 7 months and I had to explain to them what I have been explaining to the rest of them when they call and I asked the consultant to check the records on their system as to how many times I have been calling and was asked to pay R 372.00 as well and my tracker stopped work 3 weeks after installation when I called they said my account is in arrears , even though I tried to explain that it is not my fault they refused to reactive. I am getting SMSs threatening me from then saying I will be black listed . they do not have complains department line to call. They listened to the call early in January then they confirmed that it was their fault and the device only worked for less than a month when it was installed but I have to pay for 7 months in which it was not working( not fair) , they are still harassing me .