Also report the buyer to Acorn:(the Australian Cybercrime Online reporting Network):

https://www.acorn.gov.au/

 

If they get away with doing it to you they'll do it with others,(which they may already have done with all the

 

ones that he's bought),stubborn_smiley_by_mirz123-d4bt0te_zps12f1a5a3.gif

 

The onus is on them to ensure they know which ones they did and didn't receive.