is it possible to extend a done4 ticket?
 

I bought two ex-CAI tickets last year. Finished mine last month. My brother has until 23-Mar to finish his trip. He says he can't do it. Has only flown 2 of 16 segments. I cannot think of any way to extend the ticket beyond that date. I read somewhere that if one 'upgrades' to a GLOB, that might work. Any suggestions? Don't feel sorry for him. He wastes a lot of money on travel, but that is his problem.

There's no way as far as I know. Anyone who got the ticket's validity extended by upgrading it to a xGLOBxx probably was lucky and the airline made a mistake. If only 2 flights were used, however, there may be some values for refund. This depends on the published fare of the flown segments.

When the tickets were purchased and when the trip started are different. You have 1 year from the date of the first flight to complete the trip.
Were the tickets purchased on 23 March 2017 or was the first flight on that date?

no done fare was filed ex cai on march 2017

Tix bought in Nov 2016, 1st flight was 23-Mar-2017. Flown segments are QR CAI-DOH-ORD. Doubtful that there is any residual value since the cost for the DONE4 was $3500. Luckily, it was only a 6 or 7 segment bare bones itinerary.