cancellation of tracker debit order

I called tracker office in Middelburg to cancel my tracker tariffs and debit, my car was written off after the accident. They told me they can't cancel because I've got a contract with tracker for three years and if I cancel I'm liable for paying the outstanding balance of money for the period of the three years contract . Then I asked the lady that I was speaking with to email me the contract that stipulates such and where I've signed for a 3years contract, then she said only the head office can do that, they'll call me in 24 hours. Until now I haven't been called after two full weeks and no contract I signed that says 3years, everything was done telephonic and the told me where I have to take my car to, for the tracker to be fitted. The agent I spoke to never explained anything of a three years contract. I want all this to be cancelled with immediate effect, my car details: HFY868MP Renault Clio 4Dynamic, hatchback metallic grey in colour.