MIX Telematics Africa bad Service

I am a customer to MIX Telematics Africa and this organization was deducting my account for a car tracking services for the vehicle I have never owned for at least three years. When I enquire about the vehicle they seem not to care. After numerous calls I got hold of Department manager. I pleaded with her to assist and she too has failed. I want to cut the relationship with this company because they are doing nothing with my enquiry. I renewed my contract with them before I realized what was going on. I suspect they knew about this extra vehicle because when they asked me to do the upgrade no one ever mentioned the other vehicle to me. I have had two upgrades with them for my vehicles and it never happened either by mistake that one of their representative or sales consultants mentioned the extra vehicle. I take they knew about this and that is how they operate. Due to bad service I want to do away with them. This enquiry started in December 2021 until to this day 05/07/2022 no response. This company is bad.........I really want out because my unresolved enquiry.