I am being ****med

I have got a car from Europa car from my insurance (Santam) as a courtesy Car, and after all the payments and weeks has passed they call me to tell me i still owe them an amount of R2551 after they have detected amounts from my card and took the deposit which i have made peace with. However now they saying the outstanding balance is for the upgrade i have requested which i didn't because i know its a courtesy car. and for the record i didn't know about i know which group am suppose to get as it was delivered to me by the Europa.