Q: Not able to update my address (Country) in itunes account

Not able to update the address (Country) in my itunes account. I have credit less than a dollar from US store and i moved to australia and would like to update my address and card information to continue my purchases from Australian store.

I am not able to update my address, getting an error message saying "i need to zero my credit in US store before changing to a different store". I have few cents in my account which i don't know how to spend