She ordered a veg supreme for $8, but was instead given the more expensive tropical veg pizza.
When staff discovered they had mixed up two orders, they rang the other customer, who returned with the veg supreme pizza.
Aujla was then given the pizza she originally ordered but it had already left the shop's doors.
"It's a breach of food policy," she said.
"This is not a third world country . . . I just flipped out, that is disgusting. I just can't imagine what that pizza has been exposed to."
Staff did not tell her the order had already left with another customer, she said, but she saw him returning the pizza.
Aujla said the manager offered to make her a new pizza only after she complained.
The Manukau store manager, Palkaj Soni, confirmed the story.
He said he called the customer and asked him to return to the store after one of his staff made the mistake.
When Aujla said did not want the pizza, or a new one made, he offered her a refund.
"I gave her a refund and then she left the store," he said.
Aujla did not consider that the end of the matter - she called the Ministry of Primary Industries to complain.
She had not yet laid a complaint with them as she needed to talk to Ministry staff during business hours.