https://www.scienceforums.com/topic/93055-how-do-i-speak-to-someone-at-expedi%F0%9D%93%AA-your-complete-guide/
https://speakerdeck.com/oliversmith12/frontier-airlines-r-usa-contact-numbers-complete-2025-support-guide
https://telemartcall.zohodesk.com/portal/en/kb/articles/can-you-cancel-united-flights-and-get-a-refund-usa