Domino's Papakura manager Nishan Singh had not been working on Friday when the incident happened.
"That's really awful service from us," he said.
While the evening shift on Friday might have been a busy one, Singh said it was no excuse for the mistake.
"If it's a busy time, everybody has to do their job properly ... a mistake is a mistake.
"It might be somebody was careless," he said.
"I can say that we really apologise, all the Domino's staff apologise, it won't happen again."
He said he would call a meeting with his staff over the incident.
Singh said if Saini would like to come back into the store and speak to him he would ensure he got his refund and would remake the order for him for free.