Pathetic company which rips people off

I bought a car from we buy cars and gave authorization for Netstar to contact me on the 07/12/2019 of which they did. They then debited my account before they could install the device on my car. When I gave me a call regarding this they advised that the device was installed on the 03/12/2019. My question is, who gave Netstar to install the device on my car on the 03/12/2019 when I was only in contact with them after the 07/12/2019? The sales consultant from we buy cars advised that the tracking device was for the previous owner and was never taken out, why then am I being charged for installation if the tracking device was already installed? When I called to cancel my contract I kept being asked a thousand questions up till the lady I spoke to put me on hold then dropped the call. When I called again in less than 5 minutes later I was told she has already knocked off. Netstar is used to ripping people off, as for me, you're going to resolve this query or I'm taking you straight to court. I do have a contract showing that I only gave content to be contacted by you on the 07/12/2019 and I do have recordings where you advised that the device was installed on the 03/12/2019. When? How? Authorized by who?