Fortunately for us all I think, the Australia Consumer Protection legislation does not operate in ways that consider matters such as if the computer is for a new mother, whether it is their first child etc etc 

If the OP was misled about the goods he was purchasing, and based on the information in this thread it appears that they were, and that the OP actually has this in writing from the registered Australian business, then he has consumer rights, including the right to pursue a replacement or refund for the goods he purchased on the basis they included a touchscreen, and the goods he was sent didn't.