Very upset Client

During July 2019 i bought a new car with a device being installed. The car gave mechanical problems from the start and I gave the car back in December 2019. I mailed Netstar to inform them of the new car and also asked what we can do to get a device im the new car. My problem was attend to and I was told there is no fees payable. I wanted to cancel bit the settlement was over R1000 and because I was told there is no fees payable I decided to install a device in the new car. Someone phoned me to arrange installation and my network went dead. That was in January 2020. I didn't make any contact because i was told I'm in 36 month contract and I was not able to settle the amount. I paid from January 2020 until last week the 8 of September 2021. I spoke to a lady and ask her to help me with my situation. I also said to her l have paid one year 6 month for something i don't have. I have sent all the email to her. She referred it to the escalation department and im still waiting for response. My settlement amount was R400+ but my account was debited with R1090. Now I don't understand why the amount doubled. I would appreciate if someone can please explain to me why I paid double and if this is the way Netstar does business. I would not recommend anyone to do business with Netstar if this is how they treat client's. I spoke to Nokwenama and only have her email address. ***