Nightmare experience with Cartrack

The worst customer service ever. They cannot even track my application, how do I trust them to track my car. I did an application for a unit to be installed in my car with Amanda at the Newcastle branch. They advertised for R99 per month, which i signed up for. Thereafter they have been debiting my account for R161 per month. When I speak to to the customer service they blame Amanda for loading the incorrect amount, when I speak to Amanda she blames head office. Amanda has for months been telling me she has escalated the problem to management and acknowledges that I am been debited incorrectly but management is not getting back to her and she does know what to do. As a manger at Cartrack, even Amanda has no solution to the problem while keep debiting the incorrect amount.