It shows the girls, thought to be aged between 16 and 18, walking into the store and stealing chips, icecream and candy before bashing the woman and making off with cash and cigarettes.
"They had masks on and I was scared," the shopkeeper said. "One lady jumped over the counter and pushed me and she started kicking and punching me.
"She was punching my eye and I told her, 'Please, no. Take whatever you want but please, not me,' but she did not stop. I had face injuries, I was badly bruised and had bad eye injuries.
"My face was totally damaged."
Since the attack, which happened on April 3, the woman has been on painkillers but has had no choice but to return to work to make a living. "Still I am scared and I fear that it can happen again, but I have to do my job."
Detective Senior Sergeant Kevin McNaughton of Counties Manukau police said investigators needed the public's assistance to help identify those involved.
"This is absolutely appalling behaviour, and neither police nor the Papatoetoe community will accept it. We ask anyone who may know who these offenders are to please come forward."
The attack follows a spate of violent robberies in Auckland, believed to be driven a growing demand for blackmarket cigarettes which prompted Counties Manukau police to set up a special investigations unit in January.
Retail New Zealand spokesman Greg Harford said the association was receiving increased reports that thieves were targeting alcohol and tobacco, which could then be sold on the black market, he said.
"As prices go up, that becomes an alternative."
Footage from the Hari Superette was "absolutely hideous" and incidents like that robbery were increasing.
"It's getting worse ... There's definitely an increasing level of violence," Mr Harford said.
He said small, owner-operated businesses, such as dairies, often had little security, putting those behind the till at more risk.
How to help
Contact Constable Fuipu'a Mariner on (09) 261-1300 or leave an anonymous tip via Crimestoppers on 0800-555-111.
- additional reporting: Cherie Howie