Non functional car tracking device from Cartrack

In 2017 soon after buying my Renault Kwid expression 1.0, I app**** for a vehicle tracker from Cartrack and am currently paying a monthly premium of R188. Before that year ended, I contacted Cartrack to ask them to give me the location of my car but they failed to do that. They told me it was not their duty to check whether the tracking device is functional and that I should call them and request them to check whether the device is functioning. When the device was installed, I was advised by the installer to download A Cartrack App on my phone which will assist me in checking the location of my car. I installed the app but it was not functional. I tried to contact them to no avail and as a result I was unable to register. Therefore I gave up on the app and uninstalled it as it was consuming my space for nothing. The technician was sent to repair the tracker. This year, I was given a call by Cartrack to inform me that the tracking device in my car is damaged and that I have to pay R700 for it to be fixed. I asked why am I expected to pay money meanwhile I am paying a monthly premium. I further asked them why I should be the one paying since well I’m not the one who damaged their device. They said it was part of the contract and that they only provide a 1 year guarantee and after a year I will pay. I told them I will not pay the money because they are deducting their premium monthly and I do not have the money. I requested them to cancel my cover but they told me I will pay a penalty fee for canceling or bridging the contract. They refused to come fix their device and yet I am paying the premium regardless of the non coverage. Please I need your Assistance with this regard