Unauthorized debit orders

I had a free insurance with my car when i bought it in 2018 November. The free insurance expired in November 2019 and the insurance company called me offering a renewal of the contract and i rejected their offer and got a new insurance, the tracker app that i was using was even deactivated. So i got a tracker on my car from Cartrack. In 2020 March netstar starts debiting me claiming that they put a device in my car of which i never even signed a contract with them. I sent them an email asking for proof of the signed contract, they said they will review the contract and never came back with me now they are handing me over claiming i owe them. This is very unprofessional of a so called company!