YOU MUST file a complaint with the DEPARTMENT OF TRANSPORTATION.
THE airlines care about this. Delta is being predatory on their passengers and it should be recorded on the record that they are doing so.
It is EASY to file a complaint, If we get enough complaints at the DOT maybe DELTA will stop their unfair practices.
Also looking into legal action against DELTA.
Use this link to file your complaint, very easy web-form:
http://airconsumer.ost.dot.gov/escomplaint/es.cfm
FIGHT! when you are treated unfairly and most of all do not FLY DELTA anymore.