Cartrack changed my contract without my knowledge

I bought my in 2019, have had Cartrack since then. In 2022 the unit was faulty and when I called their call center they made appointment for me to take it in so it can be checked, which I did. To my surprise now when I wanted to get another unit for my other car I was told the unit in old car that contract started in 2022 which is not true and I am R167 for it but they are quoting me R100 for this one I wanted to install. I am extremely unhappy and the consultant was not pleasant on the phone.