Paying for no service rendered

I installed a tracking device with them in June 2019. I paid the first subscription in June after it was cinfirmed to me that everything was fine.

On one incedent my husband was driving the car, he realised that he was being followed. He pressed the remote panic and there was no response.

Soon after that I realised that there is a problem with the system. I did a random call to test the tracker. I downloaded their app called safe and sound it failed to track the car giving the last successful test to ***4 ( that is when the device was installed). So I was paying for nothing.

I called the customer service line and the agent was so very rude she could not help me.

I logged a complaint via email. The only resolution I received was that I should take back the car to the local service centre to determine if there was in fact a fault with their device. I did that and tge fault was rectified

But what about my money because I cannot pay Netstar for no service rendered. I send another email to cs requesting a refund on tge 13 January. That email was just ignored. So from June last year to December what was I paying for?

I would like my payments refunded to me urgently