SnapTravel’s Mr. Fazal said call volume has been five times higher than usual and its chat volume has been three times higher than usual; its average call wait time before Covid-19 was 45 seconds and now it is 7.5 minutes, he said (though travelers have complained of spending hours on hold with various agencies).

They were prepared for the wrong thing

The spike in refund requests occurred while companies were simultaneously trying to equip their own teams to work remotely, said Olivier Pailhès, co-founder and chief executive of Aircall, a cloud-based phone system that provides its technology to companies. In mid-to-late March, Aircall had a spike in calls from its customers in the travel industry.

“We had a 100 to 400 percent increase in call volume from our clients who were trying to figure out how to help people changing plans or canceling trips,” Mr. Pailhes said, adding that his company had its best week of business in March. “A lot of companies in travel have to go remote and our company is perfect for that.”

Expedia said it had to act quickly to get employees prepared to work from home to respect social distancing and shelter in place policies that were enacted around the world. The company has backup plans, but as with many industries, they were based on the idea that any emergency would be localized.

“We have a resiliency plan, so if there’s an earthquake somewhere or a coup somewhere else, we roll the calls from that call center over to another call center elsewhere in the world,” Ms. Waffle Gavin said. “But this isn’t an earthquake or a coup. This wasn’t an isolated incident. This was happening to everybody all at once.”

Some employees lacked Wi-Fi or laptops at home, which meant the company had to figure out if people could still come into offices and how to ensure they could socially distance in that space.

“The VRBO customer service team pulled off a herculean task — adding 250 agents to take calls by shifting people from other parts of the business and accelerating new hire training,” wrote Melanie Fish, a spokeswoman for VRBO, in an email.