[jimworcs]

You should file a copy of the PDF screen and the email exchange with the local Attorney General's office. Delta are anti-customer and operate on the basis that if they reject your claim, you will go away and not persist. You could also consider a small claims court claim.

You are mad to fly on Delta to London. There are loads of choices and Delta is NEVER the right one. Virgin Atlantic are good, BA, Continental are all significantly better.