rokenbach chevolet grayslake trade in a car now after two months rockenbanch wants me to pay them additional 1,647.80 is not in my contract.rokenbach said that was what they had to pay for my trade in it was more that i said.but Internet

Trade in car that in rockenbach at that time of the trade in. The sales man ask how much money i own in the car i said about1,500 but i am not sure.all the information was given to them regarding the fianace company that own my trade in.will after two month of having my new car i got phone call were they give me the news that i own them 11647.80.the reason was because the had to pay that about extra from what i said i own on my trade in.but the never call me before or send a letter to inform me about that money.i have a contract i does not said nothing about 1,647.80.
My name is victoria
city lake villa