Originally Posted by
checkerboard
As far as I've always understood it, when an agent opens a PNR (award, or revenue), they can add flights to the booking, and remove flights from the booking, in whatever order they choose. When a seat is "added" - it's no longer in the available inventory for others to grab. When a seat is removed, it's no longer available to be ticketed in the booking in question - and may, or may not, immediately, or in time, return to the inventory available for others to book from.
Of course, the change only becomes definitive once any additional fare (or taxes, or Avios) are collected, and the ticket associated with the reservation has been queued for (re)issue.
So, best practice, as I understand it, is:
a) Book the new flights, whilst keeping the old ones in the existing booking
b) Calculate the additional collection (if any), and confirm customer's consent to proceed
c) Process payment, reissue the ticket
d) Clean up the booking by removing un-needed sectors.
(C) comes before (D) precisely because sometimes credit cards fail. And in those odd cases - such a process won't leave a customer in Limbo.
Seems this isn't what happened for the OP. Not sure why some folks here seem to think the resultant Limbo is fine. It's not.