bad service paid for nothing

i had a tracker with altech nester since last year, only find out that it was not even functioning all this time. I called in to test it and they told me it is faulty and that it was my responsibility to call in every six months to check if its working. I have never felt so angry, when I listened to the recording the agent said the is no need to call netstar to test the tracker for you...now iam reliable for they mistake...terrible service I must say..