To escalate a problem with Expedia, first call their customer service at 1-800-EXPEDIA (1-800-397-3342) or use the app/website chat to request a supervisor,, as suggested by this source and this source. If unresolved, contact corporate, use social media (@Expedia on X), or file a dispute with your bank for billing issues, say this source and this source. Be prepared with your booking number, case history, and clear documentation.