Megabus is giving away free tickets to people affected by the American Airlines glitch who have had their Dec 14th-31st flights cancelled. You'll need to provide proof of cancellation to receive your free Megabus tickets:
"Email your proof of cancellation here (firstname.lastname@example.org) along with your request so that we can make your holiday wish come true.
You must forward proof of cancellation from the airline with your email. Offer valid only via email. Offer valid on cancelled flights between December 14 through December 31, 2017. Tickets valid only on cities served by megabus.com on the original travel date."