My name is ***** ***** I am a NSW Solicitor. Thank you for your question, and will do my best to assist you with your question. Please understand this is not legal advise but a guide to assist you.
I am sorry to hear but they do not have to refund you. You can send them a detailed letter and the doctors certificate and see what happens.
If you had taken out travel insurance and noted his condition the insurer may refund you but you have to look at the policy.
Also you can try contact the airline advocate and see if they can take it on and talk to the airline for you. But get the medical certificate.
Sorry I cannot give you anything more positive.
If there is nothing further
thank you for using my services.
If I have missed anything, or you have any further questions please let me know
If there is anything else in the future please do not hesitate to ask.
Please do not forget to leave positive feedback.