Hawaiian Electric Co. said Thursday that it has received dozens of reports of scam artists pressuring customers to pay overdue electrical bills by purchasing prepaid debit cards.

HECO spokeswoman Shannon Tangonan said if residents suspect a call is a scam, they should hang up and call HECO customer service at 548-7311.

“Simply hang up,” Tangonan said. “We’d never call you to threaten that your service is going to be immediately cut off. We’d never call you and demand payment over the phone. We’re not going to call you and ask you to go to the nearest convenience store and get prepaid credit cards. … We’d never tell you we’re going to meet you somewhere to pick up payment.”

Tangonan said there has been an uptick, noting the electrical utility has received dozens of reports over the past few weeks.

Tangonan said in some cases where residents call back, the scammers often pick up the phone pretending to be the utility. She said they also call people in the middle of the workday.

Loretta Yajima, chairwoman of the Hawaii Children’s Discovery Center’s board of directors, received a call Wednesday while driving. “The first thing they said was, ‘in 45 minutes we’re going to cut off your electricity,’” Yajima said. “Right away I felt very anxious and vulnerable.”

Yajima said she knew it was a scam once the caller asked her to go to a convenience store and buy two $500 cards for a Hawaiian Electric Co. representative to come to Children’s Discovery Center to pick up. “That’s when I hung up on them,” Yajima said. She didn’t pay the scammers.

Yajima said the caller was relentless. Yajima wants to warn others, “Everyone needs to be aware of the seriousness of this and how easy it is to get scammed.”

HECO said several business and residential customers have been targeted, with some paying more than $1,000 after scammers threatened to shut off their electricity.

Tangonan said the utility will began an advertisement campaign in October to notify customers of the scams.

“We really want to hit it right around the holidays when people are a little more bold with their scams,” she said.

Residents who owe the electrical utility money can pay HECO through hawaiianelectric.com.