In January, I booked a r/t flight from AUS to PHL, with connections both ways in SLC. It's in G, so first class but not changeable. Due to a change in my itinerary, I was able to make one free change. Thankfully, this coincided with me needing to stay in SLC on the way back to AUS. On Delta's website, I changed my flight from a r/t to an open jaw, ending in SLC. The PHL to SLC flight was in F class. I booked through, gave my credit card info, and was told the change fee had been waved due to the change in my itinerary. The reservation was confirmed, as evidenced in the screenshot I've attached. But an hour later, when I logged into the reservation, it only showed the AUS to PHL one way flight, with not return from PHL to SLC. When I called Delta, they had no record of my confirmation, told me I'd cancelled the second leg, and would have to pay 600 dollars to make it an open jaw. They agreed to reinstate my old itinerary for free, but now this means I'm going to have to skip the last segment of this flight, which I was not keen to do. Has anyone had an experience like this before - where you chose a seat and confirmed the booking on the website, only to have part of the reservation vanish? And do I have any recourse to get back on the O/J, free of cost, or do I just have to skip the last segment?

Did you ever get an email confirming the change? Or is the only thing showing the change the screen capture?

It's odd that it would let you change the return to SLC without charging a change fee. While you're entitled to make a change for free, that doesn't allow you to change the O/D on the ticket. Doing so should require a reprice plus change fee. What was the fare class on the return portion on the original ticket? I'm betting dl.dumb errored out thinking the return was in F and changeable, allowed the change, and then sent it to the ticketing system. The ticketing system processed the cancel of the previous return portion, but errored out adding the new PHL-SLC return in. I'm guessing ticketing system realized there should be a charge for the change, and stopped at that point seeing no add/collect. Thus the phone agents see the cancellation of PHL-AUS via SLC, but no add of PHL-SLC.

About the only issue you'll have is if you wish to check luggage on the return. It will be tagged all the way through to AUS and not just to SLC. If you can carry on your luggage I'd just leave it as is and be done with it. While throw-a-way ticketing isn't allowed, DL doesn't care unless you make a habit of it. If you don't need to check luggage just fly it how you intend.

That was my initial plan, but when the opportunity to do it "above board" presented itself, I thought I'd take it. Unfortunately, trying to do that just made one huge mess.

Unfortunately, when I received the confirmation email, that was when I knew something was wrong: it didn't show the PHL to SLC leg. I'm just curious as to why the heck it showed up on the initial confirmation page and the email. Oh well.

I think like I stated above the issue came when it was time for the ticketing system to takeover from delta.Com. Once that happened it errored out not seeing an add/collect for the change fees and refused to add PHL-SLC on the ticket.