rexee, sorry to hear the bad news
I had a similar situation at Xmas though I was mid itinerary. I know it is a different situation but I was in the US and phoned the UKEC as NAEC said they couldnt sort it. I was told that although my ticket couldn't be changed I could turn up at Dulles and plead as the CS agent told me there was plenty of availability on the flight and only a dragon wouldn't let me on. As it was a 3hr drive to Dulles I didn't risk it and in the end bought a Y ticket over the phone there and then.
The Kangaroo route is usually pretty heavy loads from what I read on here so my suggestion is unlikely to be successful. You could try phoning your TA or the EC and explain. I was treated very sympathetically with the exception of getting my ticket changed.
[This message has been edited by fbgdavidson (edited Feb 09, 2004).]