Kathy left her classic 1978 Volkswagen convertible at Freddie’s Service Station, requesting a “tune-up.” When she returned that evening, Freddie’s bill was $374. Kathy stated that Firestone and Sears advertise tune-ups for $70, and she asked Freddie, “How can you justify this bill?” Freddie responded, “Carburator work.” Kathy refused to pay the bill and left. That evening, when the station closed, she took her other set of keys and removed her car, after placing a check in the station’s mail slot. The check was made out to Freddie’s Service Station for $200 and stated on its face: “This check is in full payment of my account with you regarding the tune-up today on my 1978 Volkswagen convertible.” Freddie cashed the check in order to meet his business expenses and then sued Kathy for the difference owed. What result?