Unhappy client

I was offered a warranty for the tracking device. And when I wanted to think about it cause I don't understand why I need it, I was told that canceling my contract will cost R2000. Why wasn't I told at first before I got into the contract that to cancel will be R2000? After I have been paying my monthly premiums and sometimes you guys double charge me and never refund. Why does the device need warranty, do you guys give us faulty tracking devices and if it stops working I will need to pay R600 for a call out fee? Why are these things not discussed with us before we enter the agreement with Cartracker?