[Silent Bob]

You should definitely persue the matter, but remember you are not entitled to 800 dollars, as per DOT rules (taken from the DOT website: ***Passengers who are eligible for denied boarding compensation must be offered a payment equal to their one-way fare to their destination (including connecting flights) or first stopover of four hours or longer, with a $400 maximum. However, if the airline cannot arrange “alternate transportation” (see below) for the passenger, the compensation is doubled ($800 maximum). The fare upon which the compensation is based shall include any surcharge and air transportation tax.***) so in short you are entitled "MAXIMUM" 400, because they gave you a ticket for the next flight, before uhmmm being escorted off the premesis. It could be that once they tallied your total it didn't come to you getting 800 based on their rules of overbooking. On Delta's contract it states (to paraphrase) that if they have alternative flights compensation will be equal to 100% of the fare, no more than 400 dollars (they gave you a ticket). If no alternative, it's 200% no more than 800. You might want to try talking to a Delta rep, and before jumping into the 800 dollars what's owed, you should ask them to calculate and explain as they go along, which is what they failed to do at the service counter. They just calculated and said "nope, no 800 dollars. Security get him outta here." Also forum member abutter might be able to further explain/assist on the matter as well.