Chase Tracking, is it real or just a ****. They sucks

I installed a Beamie device on my vehicle, just to find out it was done by company called Chase Tracking. Early January I got a call from them telling me that my account with them was in arrears. I could not understand why it was in arrears as there was always enough money in my account. Upon asking how my account can get into arrears when there are money in the account, they just said there can be different reasons. When you try calling Chase Tracking there are no answer, so what happen if you got hijacked or your vehicle get ******. Now they claiming that i need to pay them more then R600 and also effected my credit profile. Can someone please tell me how to cancel that account and even if the company are legal, I never signed any contracts with them as well. They really sucks and their service are bad.