The phone — by which I mean voice communication — puts travelers at a significant disadvantage when it comes to problem-solving. But there’s a notable exception, a time when you should pick up the phone and then maybe hang up.

If you understand the difference, you’re well on your way to resolving almost any travel problem.

The phone is still the preferred contact method for most travelers. A report by Invoca, a call-tracking company, found that 65 percent of consumers would rather use a phone than email to contact a business. A survey by Google showed that on any big-ticket vacation expense, which it defines as a purchase for more than $320, consumers prefer contacting an airline, hotel, or cruise line by phone.

Attitudes are slowly shifting, but for many travelers, the phone is still the primary means of contact when there’s a problem.

Travelers favor the phone because it’s convenient and fast. I know that’s true because almost every day, I receive voice messages from consumers who have called me to ask for help resolving their problems.

My consumer advocacy site (elliott.org) requires a paper trail like the one that Meg Aidekman, co-founder of District of Columbia tour operator Trip Tribe, advises her clients to keep. But many readers say they can’t do that, offering excuses like, "I’m not good with technology" or "I’m a senior."

Travel companies seem to like the status quo, too. When there’s no paper trail, it becomes much more difficult for you, the consumer, to resolve a travel complaint in your favor. That’s because when you contact a company about a service lapse or a delay, you have no evidence of your previous contact, no record of any response. It’s the company’s word against yours.

Bigger travel businesses, such as airlines and online travel agencies, have sophisticated call-center systems that record each customer service interaction. It’s not likely that many consumers make their own recordings.

“Whenever possible, get it in writing, and document everything,” Aidekman says. “We always advise customers to deal with issues in writing, as it leaves a paper trail. You can use it to follow up on and hold companies to their terms and conditions and promises made.”

Customer service expert Chip Bell, author of The 9½ Principles of Innovative Service, says putting communications in writing can help retrieve facts that both parties can innocently and easily forget: "We all say things that fade from memory as other facts crowd them out. Think of a written record as your reference library of what was agreed."

A written record is possible even when you have an immediate request that would generally require a call. "Use private digital channels like Facebook Messenger and Twitter Direct Message to seek issue resolution," advises Joshua March, CEO of Conversocial, a company that tracks airline performance on social media. "These channels are not only secure but offer a fast and convenient way to try to solve the issue while you’re on the go."

You can store and retrieve Twitter DMs and Facebook messages when you need to remind a company what it promised. I just handled a case in which a consumer saved every online chat. When the company reneged on a promised refund, he showed it the chat transcript. It quickly offered the full refund.

But there’s an exception to the hang-up-the-phone rule, and it’s equally important. Sometimes, a phone call is the best way to reach a company. For example, when you’re planning a complicated cruise itinerary or trying to book an award seat. In both cases an agent can sometimes offer options in a real-time phone call that you might not know about if you were booking online.

And of course, after an airline flight cancellation, passengers instinctively dial the carrier’s toll-free number to rearrange their itineraries. That’s unlikely to change even if every passenger has a smartphone with the airline’s app on it. The phone still rules.

"When you have a travel problem, call the company, and if you don’t get it resolved, hang up," says Greg Trosko, an office manager from Princeton, N.J. "Call back later, and speak with someone different. You’d be surprised how often you get a completely different answer."

Trosko has used this strategy when trying to book an award ticket. One phone agent said no to his request, so he politely ended the call and phoned back. The second agent said yes.

"What’s the worst thing that could happen?" he asks. "The person says, ’No.’ "

The hang-up-and-try-again strategy is an oldie that we learn in Consumer Advocacy School. (OK, there’s no such thing as Consumer Advocacy School, but if there were, that would be one of the lessons.)

Now that integrated caller ID systems provide corporate call centers with information that gets attached to your reservation and loyalty program number, there’s a critical modification.

The big companies are on to you, so you can’t just hang up the phone and try again. That’s especially true for travel insurance companies, which document every call. For smaller companies, though, if you’re trying to negotiate a refund and find yourself talking to someone who is less than cooperative, the hang-up strategy still works. Unless the agent you’ve just spoken with documents the call in your reservation, you can start over. Restate your case, and see whether the company changes its answer. It just might.

Whether you’re trying to negotiate a refund on an airline ticket or push for credit on a future cruise, the phone can be your best friend — or your worst enemy. It all depends on how you use it. If you know when to hang up, you might get what you deserve.

Christopher Elliott is a consumer advocate, journalist, and co-founder of the advocacy group Travelers United. Contact him at elliott.org.