But the rules are very clear. A two year old MUST be held on a parents lap for the duration of the flight.
So that seat should have been unoccupied.
The parents should be getting the money from whomever was supposed to be in the seat.
The parents should be getting the money from whomever was supposed to be in the seat.
Their 18 year old son was supposed to be in the seat.
He took an earlier flight, so...there should’ve been a credit, less any cancellation fees, given to them. But, you cannot just decide you’re going to keep that ticket/seat for someone else of your choosing.
Once older son was NOT the passenger (for this ticket), airline has right to sell said seat to another passenger.
Age two is the demark, where tickets are required, at least for Delta:
Delta web site:
http://www.delta.com/content/www/en_US/traveling-with-us/special-travel-needs/children.html
Ticketing Requirements
No Ticket Required
You may travel with one1 infant in your lap without purchasing a ticket if:
the infant is less than two years old, and
you are at least 18 years old or the infant's legal guardian, and
your travel is within the U.S.2
Ticket Required
You'll need to purchase a ticket for your child when you:
have a child that is age two or older.
have a child that turns age two during a trip — a reserved seat and ticket are required for the entire journey.
prefer the child to sit in a seat with an approved restraint.
have a second child, regardless of age, and you already have a child who will be sitting in your lap.1
want your child to earn miles for a SkyMiles account.
will be traveling between countries, regardless of whether or not the child occupies a seat.
Child Fares & Special Discounts
Travel Within U.S.
Delta does not offer discounted infant and child fares within the U.S.
Per Delta, a child of 2 needs their own seat. They cannot be on the parents’ laps.
https://www.seatguru.com/airlines/Delta_Airlines/infants.php
From the mouth of the FAA:
Did you know that the safest place for your child on an airplane is in a government-approved child safety restraint system (CRS) or device, not on your lap? Your arms aren't capable of holding your child securely, especially during unexpected turbulence.
The Federal Aviation Administration (FAA) strongly urges you to secure your child in a CRS or device for the duration of your flight. It's the smart and right thing to do so that everyone in your family arrives safely at your destination. The FAA is giving you the information you need to make informed decisions about your family's travel plans.
https://www.faa.gov/passengers/fly_children/