Officers arrived at the Jersey Mikes located at 5701 Burton Station Road and found that the masked man had entered the store, approached one of the employees and assaulted him.
The employees felt that they were going to be robbed so they "attacked" the man.
"I hit him with the mop stick, broom stick, whatever. And we started wrestling around. And I am telling the other employee in the back with me, get him, you know, get him. And we started just beating him up, you know," says store manager Mike Lambeth.
The beating forced the robber to retreat through the back door. But escape wasn't that easy.
"He's trying to get out the back. We beat him up some more out the back, he's bleeding. Cars are honking at us. He's stumbling in the street," Lambeth says.
Police said the robber eventually got away and was last seen limping down the road.
He is described as a black male, late teens to early 20s and wearing a black hoodie and a dark colored bandana.
Lambeth says he and the others swarmed the robber because they wanted to stop him quickly, because this store, and the people who visit here, are important to them.
"We are not just a sub shop. We have people who come in here on a first-name basis. We know them. We know their families. They enjoy coming in here. We don't want this to be seen as an unsafe place to bring your family and your kids. We sometimes have customers eating in here after nine. We're not going to let our customers or anybody be put in danger like that," he says.