Jane was working alone at the Racecourse Dairy in Sockburn when the terrifying incident happened.
It is one of two robberies police are investigating today.
The first was reported at a business on Lillian St in Halswell at about 6.20am.
Then they converged on Jane's dairy after she alerted them to her robbery at 10am.
"I was scared, that's for sure," she told the Herald.
"A car pulled up in the disabled park outside and then they got out of the car quite quickly which was unusual.
"I'm quite alert about what's going on outside and I realised they were not good people."
"They walked in and one pointed a gun at me ... I pushed the alarm button and the alarm went off.
"Then I grabbed my phone and ran out the back door.
"I could still see them on the (security) cameras, one jumped over the counter and grabbed cigarettes and tobacco."
Jane said the men then left "in a hurry".
"They were only here a few seconds," she said.
"There were three but only one had a gun ... they just yelled 'robbery'."
Jane said since taking over the dairy a year ago she has not had experienced anything like she did today.
A police spokeswoman said both robberies are being investigated and inquiries are ongoing.
Early reports suggested several offenders raided the Halswell business, and fled before police arrived.
