The group of girls chased ninth-grader Addison Rice, her two sisters, and her mother through Mount Barker Central, after following her from Mount Barker High School.
Addison and her family were followed to a Specsavers, where staff assisted them by locking and locking the front door, keeping them safely inside.
Addison’s father, Paul Rice, said the experience was harrowing for his wife and children.
“[They] began to scream screaming, [they were] abusing her, threatening her, trying to hit her,” he said.
“One of [my] other daughters had to intervene to stop these [girls] to attack [my] youngest daughter.
“I had my wife and three daughters in that store protected by the people who work there.”
Witnesses said the group attacked the girl and left some older customers feeling unsafe.
Rice and his wife want the Department of Education to intervene, as well as the police.
Officers dispersed the group of girls at the scene, but said they would take no further action.
Mount Barker High School promised to take “strong action once full details of the incident are determined,” in a letter sent to parents of enrolled students.
Parents are calling for tougher and potentially legal consequences for intense bullying incidents.