It is unfortunate your badges have not arrived after a 6 week wait.
Your best option is to try Dave's brother Geoff, as he is helping the family with the disposal of Dave's merchandise.
But if it is lost in the mail, I am not sure that he can do anything for you.
Did you ask for tracking or insurance?
Geoff has his own militaria business and your best way of contact is thru is website below.
https://www.milimem.com/