Thanks for everyone's responses.That's right. Changes to things such as flight numbers, dates, or changing times aren't going to require a re-issue, just a revalidation: The sectors are all the same. But cancelling a whole sector - removing it from the ticket - will require a re-issue.
Once revalidated or reissued there may be a change in taxes. The agent may or may not waive those depending on the value, and whether or not the change was voluntary or involuntary.
I did call (48mins on hold) and was quoted $400 more in taxes after a further 35mins.
I'd hoped for a reduction given we're reducing the total number of flights/1 less airline and the Qatar flight to Colombo and to Doha have the same flight duration.
Given past history of issues with re-ticketing (losing QR flights/having to call 6 times to get a new e-ticket etc) just felt its not worth the uncertainty given we secured Q-Suites from Melb to Doha to start our honeymoon.
We are travelling 9/10 May.
