A tense interaction between a store manager and customer who wanted to buy a 12-gauge shotgun resulted in the manager losing her job, according to a lawsuit.

Delilah Rios resigned from the Big 5 Sporting Goods Store in Downey, California, after company officials overruled her decision not to sell an 'erratic' man a weapon.

In a lawsuit, she alleged wrongful termination and violation of labor laws, among other claims, according to the Los Angeles Times.

Delilah Rios resigned from the Big 5 Sporting Goods Store in Downey, California (pictured), after company officials overruled her decision not to sell an 'erratic' man a gun, and releasing the weapon to the customer

Rios said the problem began January 21, 2015, when she assisted a middle-aged man to purchase a firearm.

He passed a safety test, but then stormed into the 'restricted area' of the store while she processed his payment, took his identification and credit card and left.

Later that week, he returned for another gun. He said he would take 'any crappy old gun' and selected a 12-gauge shotgun, according to the Times.

He had a friend helping him fill out a federally required form documenting the sale, but Rios told him it was legally required to be completed alone.

After she said that, he grew agitated and later accused her of selling him the wrong weapon.

After the required 10-day waiting period to pick up his firearm, he returned to the store on February 4.

Later that week, the same customer returned for another gun. He said he would take 'any crappy old gun' and selected a 12-gauge shotgun - similar to the one pictured above in the stock image

Rios was working the cash register for an employee on break, and the store was incredibly busy, so she did not have time to release the firearm to the customer, reported the Times.

According to the lawsuit, he said: 'I paid for it, and you need to give me my ******* gun,' before leaving and threatening to call police.

That evening, she found unused ammunition on the floor of the aisle that the customer had lingered, and it was not a type that the store carried.

The suit said she became concerned that the man had brought in live ammunition for the firearm he wanted to pick up. She reported the incident to Big 5 corporate management, who told her to call him and ask if he brought in the ammunition, reported the Times.

The customer returned the next day, irate and yelling loudly 'You again, I hate people like you. People like you should not exist, I hope you get fired,' according to the lawsuit.

Rios said she was afraid and that she told him she would not hand over the firearm, offering him a refund.

He refused to leave, and two off-site supervisors questioned why she could not just release the gun.

A manager, who was on his day off, eventually came and handed over the gun along with a $25 store giftcard. Police were present.

Rios reported the incident to Human Resources, hoping to work at a different store. Her request to move was denied, so after eight years working with the company she resigned, reported the Times.

The lawsuit says: 'She feared for her safety and felt that money meant more to Big 5 Corporation than public safety or employee safety.

'She felt she could not work at a company where she would be forced to release firearms to people who should not have guns.'