Probably cant get a refund but if there is any DL flight that works better for you, call back, let them know the change doesnt work for you and then suggest your flight of choice.
If needed chime in with your sob story but honestly DL is usually shockingly flexible with these kind of changes.
Like others upthread I've been able to change dates, airports, routings etc for relatively minor changes - sometimes getting off of a cheap and inconvenient one stop to a much more expensive nonstop at no cost. The key is to feed them the alternative flight or lead them to the alternative flight "gee maybe you could check and see if there is anything out of CVG that could work..."