NEW YORK (CBSNewYork) -- Police say a slew of robberies at cell phone stores in Queens is putting store clerks and customers in danger.

The latest heist happened on Christmas Day.

Noel Rivera described the armed robbers as "cold hearted." They hit his Metro PCS store on Sunday.

Surveillance video shows how it happened at the Rego Park store. Two men and one woman can be seen taking a customer, an employee, and the employee's two friends to the back room while the female robber stuffs merchandise into a big bag.

One of the men can be seen stepping on a 56-year-old customer's head to make sure he stays down.

But -- the innocent victims suddenly fought back.

You can see the store employee charging at one of the robbers. His two friends join him -- pummeling the suspect to subdue him.

The friends managed to take the gun -- left on the counter -- and the gun fires a bullet into the wall.

Rivera tells CBS2's Jessica Borg that he's grateful they weren't hurt.

"Their lives could've ended behind someone's madness," he said.

Four days before Rivera's store was hit, police say robbers hit a Sprint store on Junction Boulevard in Corona.

Authorities say the incidents fit a pattern of robberies throughout queens since late November.

Rivera doesn't think they'll be on the lam for long.

"The NYPD is going to come for you, man" he said.

Police ask if you recognize the suspects, call detectives to prevent similar robberies from happening in the new year.