Sorry to hear about your situation. The problem with a HT appeal is that you don't know if it would have been successful, it all depends on the quality of the information that it is sent. I am not sure if you can do demand that the HT does a late HT appeal, I have a feeling that the deadline for HT appeals has passed.
However, I don't think it matters if you have a HT appeal or not, you still have the right to an appeal yourself and perhaps focusing your energy on that would be best. I know of children with successful appeals who have not had a HT appeal and visa versa. There is loads of information on this site about doing an appeal http://www.elevenplusexams.co.uk/appeals
you need to wait until after 1st March and then you can appeal for your chosen school on the grounds of both non-qualification and over-subscription.