Security footage of the men believed to be those who skipped out on the $291 bill has been given to the police.
A police spokeswoman confirmed the matter has been reported but said they wouldn't be investigating.
"Each case is different and is assessed on its own merits," said a spokeswoman.
"In this case, it is considered to be a civil matter."
Manoonpong said she was was disappointed police were treating it as a civil rather than criminal case.
"So what the police are implying is that in New Zealand it is okay for people to just walk into a restaurant and walk away without paying," she said.
"It is so ridiculous. I am very disappointed and upset and totally disagree with the police."
On Sunday, July 17, the three mean walked into Grasshopper and ordered whisky, she said.
Manager Joy Suwanna, who served the men, said she did not notice anything untoward at the start.
"It is very normal for people to start by ordering drinks. They also looked professional wearing suit jackets and were very polite," Suwanna said.
"But I sensed something was not right when they kept ordering drink after drink when they hadn't emptied their glasses."
Three times, the three men stepped outside for cigarettes, and each time they returned.
But the fourth time, after a dessert of chocolate revenge and deep fried banana, the trio stepped out and fled, she said.
"I ran out and they were gone. I feel totally cheated and shocked," Suwanna said.
Marisa Bidois, Restaurant Association of New Zealand president, said customers leaving without paying was "not acceptable".
She said it was near impossible to determine who was a dine and dasher, but owners needed to be vigilant.
"There's really not much restaurateurs can do, unfortunately, except to be more wary and alert."
Bidois said it was disappointing the police were treating it as a civil matter because it was theft.
"It's essentially using a service and not paying for it."
Bidois said the association will be surveying members to find out how widespread the problem with runners was.
