The formation of a contract

You are in the train station waiting for your train to arrive. You see a vending machine from where you
can buy snacks and chips for $3.50. Posted on the machine is a sign saying: “Property of XYZ
Vendsolutions Pty Ltd”. You insert the coins required into the machine and out comes a packet of
chips. However, when you open the packet of chips, you find bits of plastic inside and you don’t want
to eat the chips. You want your money back.
Required:
With reference to the essential elements for the formation of a contract, explain:
a) Did you enter into a contract in this scenario?
b) If your answer is yes, with whom did you enter a contract?