One afternoon, Amber was sitting in the train station waiting for her train. She felt very thirsty. On the platform was a vending machine owned by Express Vend Solutions Pty Ltd. The machine was selling ice cold drinks. Amber couldn't resist. After checking the price on the machine ($3.50 for a can of cola) and that she had the correct change, she inserted the coins in the machine and pressed the button. The machine accepted the payment but did not give her a drink. Advise Amber whether a contract exists and with whom.