You do not get to use something for 12 months and then get a refund

Even if it was an Australian seller without an overseas import, there is zero warranty if they are not an authorised seller

What can you do?  avoid buying something like a phone of any price from a random on ebay

The time limit for the MBG for an item not as described is 30 days, not a year

And if you didn’t know for a year what you bought, the seller may just as possibly been unaware what they sold

Was the phone in the original box?

Did you need an adaptor plug?

Didn’t anything in the phone settings indicate it was an overseas import?