Originally Posted by
WhiskeyBravo
Since you purchased through the Delta website I would try one other thing --- try to change the ticket on Delta.com. See what math they present you with through the web portal if you open your reservation and click change and then pick some new flights. The user interface isn't all that great but you will land at a screen showing you the final math before you have to commit to anything.
This is exactly what I was going to post. Delta's website is better than most at changes. See what fare options are available on the website.