It's the second time in just over a month the dairy had been robbed, Singh said.
The first robbery, on February 23 around 6.30pm saw cigarettes and money stolen by someone weilding a knife, Singh said.
Singh said he didn't know how to increase security as he couldn't afford to have two staff working all the time. He suggested a higher police presence.
"I don't know what else we can do," he said.
"We just want police to do something. They could have hurt her [Preet] and she can't just leave. Someone has to work here. It doesn't matter who it is, it's not safe."
Police want to hear from anyone in the area at the time of the robbery or anyone with information that could help.
They can call Rotorua police on (07) 349 9590 or call Crimestoppers anonymously on 0800 555 11.