Originally Posted by
CPH-Flyer
Sounds like your I class ticket had a restriction to be not changeable after departure, and they are selling you a one way D class ticket instead. The devil will be in the details of the conditions of your original booking. But my guess is that after first legs flown, remaining fare is "lost" for changes.
So Egencia made a mistake. According Finnair it was only the fare difference + 200 €. I changed the iternary with one day and booking class I became available. It was hard to change it, you can nowhere find it yourself and Egencia wasn't helpful. I ended up looking ITA matrix for I availability and had to tell Egencia exactly which flight they had to calculate.
I remember that when booking with Finnair this is easily done through the website. What is the value of Egencia?