I am being charged for a service im not recieving

I called Cartrack last year to have a tracking device installed, a technician came and installed the device, i asked him if the device comes with a remote button he said no so i left it at that, after the instalation i kept recieving phone calls from Cartrack where they were sking me if i had my remote with me i kept telling them that i dont but they kept calling and telling me that i was supposed to have been given one. Early this year my device was scheduled for a maintenance check and the technician that did the check mentioned that the device in the car is not the device im paying for it is infact a cheaper package, i called in to Cartrack and to this very day no one is willing to assist me, i want out of the Contract.