Cartrack stress

I am in kind of a trouble or I am stupid. November 2020 I took a tracker package with cartrack and I took my vehicle for installation of a unit. On my arrival at home I notice that the dashboard skin clips were broken and vehicle started to drain the battery. I downloaded cartrack application on my phone to link the unit on the car, but was unable to connect than I called the center and the lady who was helping me explained that the unit does not appear on their system.

On month end of November 2020 account department called me and I explained that the unit is not working and I cannot pay for unrendered services. My call was escalated and they arranged and a date was provided,but the date did not suite me and asked them to reschedule.

No reschedule was conducted but each and every month I received calls from cartrack account department instructing me pay the outstanding balance and I kept on telling them I cannot pay for something that I am not using.

I went to the extend that I want to cancel the contract but they are demanding the amount of R2600 for the cancelation.

I mean I did not breach the contract and they did not delivery. I just want to know who is at fault.

I am thinking of approaching the consumer court for advice