Replacement 4S abroad

Hi all

hopefully someone can help with this

So i have an iphone 4S, still under warrenty and was brought in the UK unlocked. now living in Australia

I have had the phone for 6 months and the white paint around the edge has started to wear of. I took it to the genius bar in Australia and the guy said he can replace it, then said he cant because it is a UK iphone and the system wouldnt allow him.

he recommended as its a UK iphone i should call apple care international and they may be able to help, I rang them and they said as its a uk phone there is nothing they can do, he said if it was an iphone 4 or 3 then it would be ok, but not the 4S? this makes no sense to me

I have no plans to go back to the UK, but clearly as this is warrenty issue there must be something i can do?

Any help would be much appreciated