Netstar Demanding cancellation fee after a car accident

Netstar is harrassing Me. I have an accident on the 26th of April and fortunately my life was spared but my vehicle was damaged beyond repairs. I have been paying netstar without missing a payment for the duration of 3 years since I bought the car since the car I bought was already installed with a tracker from netstar. The contract I had with netstar was month to month. Already on the time of accident they had their money which was for April. From the first of May I did not have a car and I don't remember tracker calling me to say we can't locate your car. All the insurance companies I had insure my car with refunded me. For the money they debited on the 1st of May. Netstar claim that I was supposed to give them a month notice. So my question is , was I supposed to know that I will be involved in an accident so that I will give netstar a month notice. How can they expect to know that I will have an accident. They should know where my car is I don't know. I paid them honestly so and now they treat me like a ******** calling me every day that I owe then cancellation fee. It was not intentional that I had to cancel their contract.