A company that ****** people

I cancelled cartrack over the phone in March and they said I needed to pay cancellation fees which I paid. They told me I missed a payment again in April and again told the call centre I'm cancelling. In June I sent forms and an email to have proof and I'm again being told I owe them. No matter how many times you cancel they don't action cancellation on the system they instead force you to pay for service you don't need