"Dear tangoll

Thank you for allowing us the opportunity to address your concerns as forwarded from the US Department of Transportation. At Expedia, we take customer complaints and feedback seriously, and strive to provide our customers with a great experience.

Our records indicate that on July 3, 2019, you, or an authorized user of your account, self-booked a one-way flight reservation on Expedia’s website, under itinerary xxxx. Travel was with American Airlines, departing on May 3, 2020, from Hong Kong, Hong Kong SAR to Los Angeles, CA, United States. We understand you are requesting a refund of your unused flight reservation.

Upon receipt of the complaint, we can confirm that on April 20, 2020, a full refund was processed for your cancelled reservation. The refund timing usually takes up to eight (8) weeks to be issued back to your account; however, due to the unprecedented circumstances, refunds might take longer.

Again, we thank you for allowing us the opportunity to address your concerns.

Signed XXXX
Corporate Correspondence Team"

So, what are the lessons to be learned from this saga:
1. US DOT demand for a response resulted in action from Expedia's Corporate office.
2. Despite repeated corrections, Expedia personnel just cannot get what the correct facts are.
3. Do what you think is best for your own interests, and ignore comments from other posters in this forum who say they know better than you as to what your own interests are.
4. Hang in there and persist; emails do achieve results and save you from frustrations of having to deal on the telephone with Expedia staff or supervisors from having to wait, getting cut off, trying to put you off, etc.