On March 8, Sharon spoke with Johnson, the manager of a local car dealership, and was informed by Johnson that a car she wanted to purchase would be available in about one week. Johnson wanted $32,000 for the car, but agreed to sell the car to Sharon for $30,000 with a $3,000 down payment with the balance due upon delivery.Sharon immediately wrote out a check for the $3,000 down payment and mailed it to Johnson. Johnson promptly cashed the check. When Sharon called the dealership a week later to inquire about the delivery of the car, Johnson told her that he could not sell the car for less than $32,000. The next day, Johnson sent Sharon a check for $3,000 with the following notation: "Return of down payment on the sale of car." Sharon immediately sued the car dealership for damages.

Please explain.