Bullying

I had 3years contract with cartrack. After 3 not gud year with them I sent them email to cancel the contract but they kept on deducting monthly I sent them another email that I didn't authorize the debit order. They told me I have to cancel over the phone. I called and canceled they told me I have to pay for 2months before they cancel.I returned the debit order for 2months cause I have been requesting Since April 2020. Now they bullying me with calls 10th times a day.