Restitution for what? Your children appear to be alive and well, and they made it to their destination the following day. What did you lose? Did anyone experience irrepairable (sic?) harm. Sure you have a right to be angry, but this all happened several days ago. Save yourself the $$ a lawyer will charge you, and move on. Any recovery which he might make on your behalf,, especially if it is the form of vouchers with questionable long term value, will almost certainly be < the cash fee he will charge.