I got nailed by DL on what became a throwaway. A day trip BWI-ATL was about $1100, but I booked two nested trips, with the returns occuring several weeks later, which I inteded to use. The fare for the two trips was about $320. I was unable to make the second trip.

About 8 months later, I got a charge on my AMEX card for an ADDITIONAL $1300! (This was the max fare for the route.) After 6 months of disputing, I got my travel agent to eat the charge since they booked the tix in the first place and I specifically asked if this was legal.

There outta be a law. . .