Hawaiian Telcom customers continue to suffer billing problems and long waits on service calls as the new owner battles glitches that have persisted since it took full control of state's largest phone company in April.

Many people dialing customer service centers yesterday received busy signals during a surge of calls caused by the latest billing problems, said Hawaiian Telcom spokeswoman Ann Nishida. The high volume and busy signals could continue throughout the week, she added.

Even before the latest episode, callers complained that they waited 30 minutes or more for customer service. Hawaiian Telcom added temporary staff, including 120 hires to help with billing inquiries, but the company is still unable to answer every call promptly.

Hilkka Easterwood, a Hawaiian Telcom customer in Kaka'ako, has been unable to contact the company with billing questions.

"It's just impossible to get them on the phone," said Easterwood.

"I left a message, and it took them two days to call me back. When they called back, I wasn't home. I just paid the bill because there's no way to question them. There's nothing I can do about it."

Hawaiian Telcom had pledged that the switch from the company's previous owner, Verizon Communications, would eventually result in better service and new products. Hawaiian Telcom spent $100 million to bring Verizon's back-office operations to Hawai'i and integrate systems to speed up customer service, including opening a local customer center.

However, the transition has been rough because of the complexities in switching services from one company to another.

This week's problem results from software errors that caused April and May bills to go out late to customers. Hawaiian Telcom waived late fees for April and May. But the billing problem meant less time between bills. In many cases, customer payments for the prior month were not credited to their account before the next bills were sent, Hawaiian Telcom said.

That meant April charges carried over to May bills, and May charges may carry over to June bills. Customers who paid their previous months' bills should only pay the current charges, Hawaiian Telcom said, and they do not need to call the company. The company could not say how many customers were affected.

"We apologize to customers for the inconvenience and frustration they are experiencing," Nishida said. "Hawaiian Telcom is working hard to get caught up and normalize billing schedules, which the company expects to have on track in July."

Hawaiian Telcom's latest customer service issues come nearly three months after it officially severed ties with Verizon Communications. Before April, 90 percent of customer calls were answered within 20 seconds.

Hawaiian Telcom's owner, The Carlyle Group, an equity firm based in Washington, D.C., paid $1.6 billion for Hawai'i's major phone company in a deal that closed in 2005. The company also plans to offer a television service via high-speed phone lines.

The company's problems have left Hawaiian Telcom customers like Louise Frye frustrated.

"I pay all the bills before they're due, but before I mailed them a check, I received the next month's bill that indicated a default," said the Pupukea resident. "They don't know what they're doing. We pay our bill, but when you get a bill from them, you don't know what you owe. It's terrible."

Reach Sean Hao at shao@honoluluadvertiser.com.