UPDATED 2.12PM: Peeved passengers remain grounded after Jetstar's big computer breakdown.

The budget airline says operations have returned to normal after an IT outage caused serious delays yesterday.

But Sydney-bound passenger Billy says he's been delayed for 22 hours, with his flight re-booked four times.

"This 88-year-old lady has literally been stuffed around the entire night.

"She's only had three hours of sleep."

Billy says he was even re-booked on a non-existent flight this morning.

"We went in to check-in again, and they said the flight doesn't exist. They said it was yesterday.

"So then we had to go and re-book."

He says the communication between head office and airport staff was very poor.

"You could literally hear [the head office] over the phone, talking to her.

"We saw the look on this poor girl's face."

Billy says Jetstar have moved him to a Qantas flight, which he hopes takes off on time at 12:30pm.