Agreeing with others.,..tell ABD that their alternatives don't work and firmly demand a complete refund. Keep your airline reservations as is and plan your own trip to DC and Philly. Both are incredibly easy cities to visit. In DC stay at a hotel near a subway station - system is so easy to navigate (buy a replenishable card). Take 2-3-4-5 days on the National Mall - too many places to mention and many are free. Cab or Uber if you want to see something outside walking distance (Arlington or Mount Vernon). Then hop on AMTRAK for the trip up to Philly. Stay in the historic area and see the birthplace of America - tons of things to see and do there, too.