Herta Kriegner, a graphic artist from Austria, likes the German word “uber.” It conveys, she told me recently, both a European sensibility and a sense of going “above and beyond” for a customer. In fact, she likes the word so much that 15 years ago, when she started her own small New York design firm, that’s the name she gave it: uber.

Naturally, Herta listed uber’s number in the Manhattan phone directory. She set it up so that after three rings the calls were routed to her cellphone. Her sister, Elena, a jewelry designer, also used the uber office space, and the two women shared the phone number. For the next 12 years, this arrangement worked just fine.

Then, about three years ago, another Uber moved to town . Uber Technologies Inc., the app-based car company that is competing with taxies in cities all over the world. In New York, a city where the taxi monopoly has meant a chronic shortage of cabs, Uber has become very popular.

But unlike uber, Uber does not have a phone number listed in the Manhattan directory. Like many online companies, it believes in the efficiency of communicating via email. The messy business of actually talking to people, well, that’s just so old-fashioned, isn’t it?

Just because Uber doesn’t want to talk to customers, though, doesn’t mean customers don’t want to talk to Uber. Sometimes there are problems that scream for human communication: an accident, a cellphone left in a car, a mixup with a bill. And sometimes, even though online communications may be more efficient, people are simply more comfortable talking to another human.

Which is how it came to be that Herta and Elena Kriegner became experts in Uber’s customer service, or lack thereof. When customers or drivers tried to find a number for Uber in Manhattan, they often wound up with the number for uber. At first, the calls came every few days. But as Uber has gained in popularity, the calls have come more frequently. Herta showed me a phone log listing more than 500 Uber-related calls that her little company has received just since August.

“I already had my first call this morning,” Herta told me when I went to see her and Elena a few days ago. “It was 8:30. A woman wanted a ride to the airport. I told her she needed the app.”

She and Elena have gotten calls from drivers who are having trouble with their applications, or questions about their insurance. There are mornings when Herta wakes up, turns on her cellphone, and hears a voicemail from an unhappy Uber customer spewing expletives. Recently, she had to go to court to prove that a driver trying to get workman’s compensation was suing the wrong Uber.

Early on, when Uber first learned of this problem, an executive named Ed Casabian told her that it was all because Yelp had mistakenly listed uber’s phone number . and that when it was removed all would be well. The number was removed, but the calls kept coming. A short time later, she bumped into Casabian at a trade show, where Uber had a booth. She asked him why the company didn’t talk to its customers or drivers.

“Because it’s not in our business model,” he replied, according to Herta. Thinking the issue was cost, she suggested that Uber set up a call center in India. “We don’t want our customers to talk to someone in India,” said Casabian.

“You would rather have them talk to me?” she asked.

These days, Herta and Elena get between one and 10 calls a day. Not long ago, a woman called to report that her daughter had been harassed by an Uber driver, and what should she do? Elena told her that Uber didn’t talk to customers, and she should instead go to the police and then to the news media. (In a statement . emailed, of course . an Uber spokeswoman said that the company’s “average response time” was less than an hour when customers emailed them with problems.)

As annoying as the calls have been, they have taught Herta and Elena a few things about what constitutes real customer service. One lesson is that many customers are always going to be more comfortable explaining a problem in a conversation with another person, rather than an impersonal email. Yes, it’s inefficient and cuts into profit margins, but companies that actually care about their customers do it anyway. Zappos’s customer service number is on its home page. Amazon’s isn’t hard to find either.

This week, Uber raised $1.2 billion, giving it a valuation of $40 billion. The company’s chief executive, Travis Kalanick, said that some of the money would be used to continue its breathtaking expansion. He also said that the company needed to “invest in internal growth and change.”Here’s a suggestion: Hire some people who will answer the phone.