Incompetency on deductions OVERPAYMENTS!!!

I have upgraded from netstar Neno to the package that has panic button , from the information I have when I bought the car was Neno package has been paid by the dealer until 3 years but I was re-calculated and requested to do a top up of R95 a month to accumulate the R199 package . But only when I see december I paid R300 and something which I assume it’s arrears but how every month R95 it is deducted , lastly jan R199 and R95 was deducted so meaning I am paying for nano and the Panic button package . Can someone explain to me how does your payment request to bank works and the creditors team in reconciling those payment , I cannot be paying for 2 units as the installer cautioned me that because the Nano unit was not requested to be removed it will be deduction .