I recently purchased a used car from a certified used car dealer in New York state, two days after I already had the car home they say I still owe them money from the down payment they forgot to collect,am I still legally obligated to pay the remained ? Also they only gave me one key for the vehicle are they legally responsible for another one?

No, they are not legally responsible to give you more than one key to the vehicle.

Did you get a receipt for any money you gave them for the vehicle? Did you get a copy of any paperwork you signed? Did they complete a purchase agreement and have you sign it?

am I still legally obligated to pay the remained Hello flat:

If they made a mistake, then you are legally obligated to pay.

excon