Final demand for payment

I received an email of final demand of payment from Muhammed Mangera about an outstanding account.My car was a write off months back so I stopped paying for my tracking device with Altech Netstar.It emerged afterwards that I am still liable for the account regardless of the fact that the service provider is no longer rendering the service for me.I was not aware of this as I did not receive a copy of the contract agreement from the service provider.The consultant i dealt with telephonically also did not explain this loophole clearly.I have since requested Altech Netstar to furnish me with proof that I received the contract and recording of the telephonic conversation i had with the consultant when i took out the policy.This has not since happened.I feel my consumer rights are being violated and therefore I am not liable for the outstanding amount.Please assist in this regard.