Matrix tracking unit

I have requested call out from matrix to come to install tracking unit on my bakkie last year,they send a technician to come to my house and he came ,he installed the unit and I asked him to test it for me to see if is working and his respond was that “the unit is working perfect “after he left ,I test it myself but no one was responding until today,I called in to matrix to notify them about the fault from the day was installed,the said to me that they will send back the technician and they didn’t ,I called the technician on his personal phone ,he said to me that ,he cannot come back until they tells him to come back,I drove to one of the branches and they told me that they cannot assist me because it was not installed by them at the branch,I called back to head office and they told that they logged in my call,they will send a technician,even today no one came ,today I received a call from a certain company telling me that am owning matrix R2200 for the tracking unit,apparently they handed over my account to the credit collector,they want me to pay something which is not working for me ,meaning if I was hijacked ,they were going to say they did not receive any signals because is not working,I want to know if this is how the operate because is not fair to us and the service is bad