Originally Posted by Cory6188

DL's eCredit tracking system certainly leaves something to be desired - I'd say the credits show up in my account only about 70% of the time.

Honestly, I think getting anyone at DL to try and unwind what happened may be near-impossible, even with a DOT complaint (but you can try, certainly). I think your best bet may be to go into your e-mail inbox, trash, airline receipts folder - wherever you keep e-mails from Delta - and do a blanket search for "006." Every credit at DL is going to be tied to an 006 ticket number, so it should be in there somewhere (through every reissue, cancellation, etc., the ticket number will be reflected in an e-mail) for any itineraries pertaining to this trip.

Go to DL's website to the eCredit/vouchers page, go to the manual lookup function, and start typing in the 006 numbers from your e-mail and see if anything pops up as having value. It's tedious and annoying, but the brute force method may honestly be your best bet. I've "lost" credit on DL before that no agent was able to help me find, and eventually tracked down which 006 number it was associated with via the above method. Honestly, I had to re-read your post a few times to try and wrap my head around what happened, and I'm still not 100% sure I get it - so even with a DOT complaint, I think an agent *still* might struggle to track it down through all the exchanges, even with their best faith efforts.