went to the car dealership last sunday to trade in my car for a van, signed all the papers for financing but..

THE NEXT DAY THEY WERE STILL WAITING FOR APPROVAL.NOW I ALREADY HAVE THE VAN AND HAVE HAD IT FOR 5 DAYS NOW.STILL WAITING FOR APROVAL THOUGH.MY QUESTION IS WHAT IF THERE IS NO APPROVAL??WHAT IF THEY SOLD MY TRADE IN ALREADY?CAN THEY REQUEST TO HAVE THE VAN BACK?