Success is good. But too much success can leave some people grumbling.

Take Independence Blue Cross. The region's largest health insurer anticipated enrolling 100,000 new members in Pennsylvania and through AmeriHealth New Jersey when the Affordable Care Act marketplace opened in October.

As of April 30, the company had signed up a total of 283,000 members in new plans, almost three times as many as it expected. And 89 percent of them have paid their premiums.

Great news, right? Well, sure, unless you are among the many people who have telephoned the company and been stranded on indefinite hold with customer service, or been unable to access the company's website, or who didn't receive an identification card, or were enrolled in the wrong plan.

Success to you probably feels more like incompetence.

"We are personally reaching out to our customers and saying, 'Sorry, here's what the factors are on hold times,' " said Stephan Roker, Independence's senior vice president of service operations. "All the projections we were given to use we had to amend very quickly."

Underestimating its enrollment caused a domino effect for Independence. Difficulty getting through on the phone led to a 400 percent surge in e-mails that overwhelmed the website, causing a 550 percent increase in Facebook comments complaining about being unable to get through.

"Every time we turn a corner, the volume [of new members] increases," Roker said from Independence's state-of-the-art call center in Spring Garden. "We're always busy, but this has been beyond our wildest dreams."

From Jan. 1 through May 2, Independence averaged 25,000 to 30,000 phone calls a day, including a peak of 40,000 calls on one day. That amounted to a 75 percent jump over the same four months of the previous year.

During those four months, having someone answer a call took an average of 15 to 20 minutes. Most calls are now answered in five minutes, executives said. There were some cases in those four months, Roker said, in which people were on hold for two hours. That still happens because of the length of the calls, but it's less frequent, he said.

To help ease the backlog, Independence initially increased its phone staff by 20 percent. When that proved insufficient, the company added more people, eventually increasing its customer service staff to 600, a rise of 50 percent.

"We do a lot in terms of hiring and looking for people with customer service in their DNA," said Renee Rhem, Independence vice president of customer service.

New hires go through eight weeks of classroom training followed by four weeks of taking live calls under the scrutiny of instructors. Graduates move to the call center, where they become part of a 12- to 15-member team that includes a technical adviser and a team manager.

The call center, decorated in soothing tones of blue and gray, stretches across an area the size of one-and-a-half football fields. Customer representatives work in low-walled cubicles designed so they can talk to and learn from one another, and have two computer screens to allow them to access the full spectrum of callers' information.

But it isn't just the number of calls clogging the phone lines - it's the length. Calls run on average 25 percent to 30 percent longer than average, Roker said, because many customers are buying insurance for the first time and aren't familiar with the language. They need to be educated about how things work. Others are accustomed to having a human resources department handle their health insurance issues. But, mostly, people just want to be sure they have the right coverage.

"Health care is very personal," Roker said. "When you are talking to someone, you are talking about their fears and anxieties. What we are learning is that consumers want to talk to people."