Just echoing Trevor.
Niece and family in Darwin ex ML, return with VA roll up to return and told "flight XXD, rebooked in 6 days time OR will refund your original VA fares".
Couldn't hang around 6 days, took the refund and $6500 later ($1300 x 5) arrived in ML with QF.
It may be that all airlines are xxx flights but reckon you'd always remember it was VA that really, really f**ked you around and cost thousands of $$.
Cheers.