Cartrack on wrong track

I was told that the contract is only two yeara but to my surprise I found out it is three years. I cancelled the contract in May 2024 but Cartack told me that the contract was only cancelled on the 15 July 2024 and the contract end in September 2024. Then it was cancelled on 15 June 2024. When I spoke to the agent at Carteack regarding the cancellation he insured me that the cancellation fee will be for the remainder of the contract which is the three months. Now Cartrack is saying that they can charge whatever they want for the cancellation fee. The service was bad. I need to pay the cancellation fee plus the remaining fees for the contract. This is day light *******. They want to double charge me now. The agents at Cartrack refer me to the terms and conditions which contradicts what they are saying. First the payments get paid in arrears then they change it to in advance. They dont even know what is going on in the terms and conditions.