Being harrassed for services I did not receive

I purchased a new vehicle which came fitted with a cartrack device. I notified the dealership in December that I am not interested on taking over the account with cartrack as I they have terrible customer service. The agent notified me that she made cartrack aware that I will not be taking over the account. I collected my vehicle in January and end of January I get a message saying my cartrack debit order came back unpaid. I called cartrack to find out why they are trying to debit my account after I made it very clear that I will not be taking their business and I was given proof from the agent that the communication was sent. Despite having also sent an email to cartrack to have the issue resolved I and my family are being harassed by this company. Please do yourself a favour and don't take cover from these ******!