matrix tracker billing nightmare

matrix billing nightmare worsen every month, so in march/april I called to let them know I cannot procced with using their services anymore due to affordability. I was called in august and there was an arrangement in place to settle the account and remove device for R700.00. same month end, my account was debited R1400.00 and the explanation that I got was that device can only be deactivated when the full amount that accumulated from 200 to 2000 was paid.. what is the point of making arrangement if there is money that is still accumulating???? I cannot make payment as things stand but ish is till accumulating????? received a call from Simon who advise me that they will be handing over my case due to none payment. I will not recommend people to use this service, it is horrible and nobody deserves to go through this. either they remove their device and I pay initial balance of 700 or they take me to their attorneys and I will pay R100.00 is its the only amount I might be able to afford monthly.. whoever replies to this must have answers and solutions, im tired of explaining the same this over and over again.