Hi. I had MEL-LHR on May 26th (return Sep 21st). Booked via online site. Had the 2 x 23kg economy ticket.
First I was offered Qantas by the agent for the missing leg, but that soon was withdrawn. Then refund. Then no refund, if you want to change it'll cost you (they didn't seem to know of the route cancellation then).
They were saying you might get a different flight, but lose the 2 x 23kg.
I had suggested the Singapore option (if they could get me the 2 x 23).
Finally i day, multiple calls & emails to agent and Virgin, they (agent) have suggested Singapore! Grrr. Waiting to hear if they will do it. Don't like my chances.
This seems so much in favour of the airline. If a passenger tried to change something like this they'd pay through the nose as a penalty.