Paying for a tracking unit that doesnt work

I phoned tracker to have my unit tested as i suspected it was causing my car battery to run flat. I spoke to sophie to assured me that i would receive an sms within 3 working days. its been almost 2 weeks now and no sms. I phoned in again and spoke to Nomsa who said that they could contact the unit hence a technician has to come out. Now she also advises that i will be billed for the cost of the technician to fix the problematic tracker unit. Why do i need to pay for the repairs as i am still paying a monthly fee for a unit that doesnt work. Surely tracker should incurr the repair costs.<br> <br> Very dissatisfied with the service. Looking at cancelling with tracker.