My wife and kids want to come to Canada as we moving permanantly to Canada

She booked a flight from Melbourne to NZ (Through Virgin airlines) and from NZ to Canada (Through NZ airlines)

today she informed that Flights to Canada has been cancelled.
and Virgin has changed direction to Brisbane first

There is no point for her to get credit as we leaving Australian permanantly

How can we get full refund?

Do we need to go to court to get full refund?

we do not want trouble. but flights cost big money and no point of having credit.

What can we do?

Contact the airline, if you get no joy there, contact your insurers.

No insurance

Have you contacted the airline? Why on earth would you not have insurance?

Were the two flights booked on one ticket, or were they ticketed separately? If separate tickets, which flight was cancelled, the Virgin one or the Air New Zealand one?

Virgin is separate. and we called them they said they just refund as credit

don't know what to do with this credit !!

So Virgin didn't cancel the Melbourne - NZ flight? If that's the case you'll need to read the 'conditions of carriage/fare conditions' attached to your booked flight. Many airlines don't allow refunds if it's the customer who cancels, particularly for lower priced tickets.

Has Air New Zealand offered a refund for the flight they cancelled?

They did not cancel it but redirect it.
it became Melbourne-Brisbane Brisbane-NZ

Redirecting a flight has no impact on the conditions attached to the purchased fare. What do those conditions say about refunds?

We called they said, they cannot refund us as the first ticket was purchased before Apr 2020 (before Virgin went bankrupt and bought by another company)
but when we asked to refund the amount we paid after Apr 2020 they still say they give credit

Ken, get the electronic ticket up on your computer/phone. Read the conditions attached to the fare. What do those conditions say about refunds?

Any reason you did not book direct from Melbourne to Vancouver? (from earlier posts you are in BC)

Much easier and they are still flying......

There were no flights

What was the reason given for the cancelled flight to Canada.and any news when flights will start to go ahead again to canada if it's not long can you rebook the flights with the credits offered? If no insurance then maybe you can claim some monies back.(if paid by a credit card) from your credit card company. Good luck