It isn’t a matter of it being locked, but rather the frequencies that it can connect to.
The Telstra network runs its 3G primarily on the 850Mhz band with 2100Mhz in a few areas to help boost the coverage (mostly in metro areas to make the network more robust) - meaning in some area you might find you get 3G on Telstra but minimal places.
That particular phone doesn’t support 850Mhz, only 900Mhz which is what VF and Optus networks use as their 3G standard so would likely work in more places.
3G (HSPA+) : 900/1800/2100 MHz
It should however do ok on 4G coverage which would allow data access but not calling.
As far as a refund that would be at the discretion of Woolies as the merchant (the one who took the funds) or contacting support and see if they will do it
http://livechat.boost.com.au/ however it is going to be most likely a judgement call from them as it isn’t a failure on their end.
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