Car written off but i still need to pay for tracke

My car was writen off by my insurer following a car crash on the 09th of Feb. I have an account with tracker which was taken over the phone, when i called to notify them that i dont have a car anymore due to it being written of i was told i would still have to pay for the tracking services because im on a 36month contract. The terms of which were never explained as i had taken it up telephonically after they called me during one of their special. I find this very ********* becasue im having to pay for a service they not providing anymore because my car is siting at a s****yard. It wouls make sense if i was paying a reduced amount for the device minus the tracking services as they not tracking any car. When i called to enquire about the contract the lady i spoke to said the terms of the contract are on their website and i should have read them there. I would really like some clarity with regards to this, why am i paying for a service that im essentially not getting. Im not even sure if this even falls under legalised theft!!