Different baggage weighing

My wife flew from Gold Coast to Melbourne for a connecting flight to Thailand. Weight from GC was 21kg. Same bag weighed in Melbourne was 25kg so they made my wife take 3kgs out. They were arrogantly unresponsive to my wife's bag being allowed from Gold Coast. After taking items out she weighed at different check in to find she could add 3kgs back. Such a lack of humanity from the staff.
I stopped flying with Qantas 20 years ago and we will never fly Jetstar either.

Australia-Gold Coast