Thanks heaps guys in fact after about 6 email messages I rang Australia post YES customer is being difficult YES customer has a poor record of leaving neg feedback lol item packaged too well item not packaged well enough lol  special list already mind this is all after customer also got a good discount on top of lower priced item.

As for what they paid for postage cheapest way possible.

there is NO air mail from Sydney to Perth or in fact available within Australia to Australia

again thanks for your replies