Regarding the poor customer service - that's a shame.
I bought a bag at the Narita Airport store in 2007 and the buckle broke in about 2009-10. I took it to the Castlereagh Street store and they sent it to Italy to be fixed. I didn't even have my receipt anymore, just a credit card statement so I was very grateful to them. They've always been really good when my mum has had problems, too.
Iwould keep persisting if I were you. Six months is not good enough - I dont think a keyring from Target would even break in that time!