A Brisbane man who booked four cheap first class flights to the US due to an error on the Qantas website was shocked when he was hit with a more than $100,000 bill after the national carrier promised to rebook customers on business class at no extra cost.

Qantas sold hundreds of first class fares between Australia and the US for up to 85 per cent cheaper than usual in the early hours of August 23 by mistake.

The airline, which under its terms and conditions can cancel and refund customers if there is “an error or mistake that is reasonably obvious in the fare price”, instead promised to rebook passengers in business class at no additional cost “as a gesture of good will”.

This meant affected customers still scored seats up to 65 per cent cheaper than the usual business class fare on offer.

Qantas sold hundreds of first class fares between Australia and the US for up to 85 per cent cheaper than usual.AFP via Getty Images

However, Aji Paul and his family, who had begun planning their holiday and informing friends from the States they were coming to visit, were devastated when the airline failed to follow through.

Mr Paul had booked four first class return flights to Dallas, Texas for his family next year for about $17,500 and used Qantas’ ‘Book Now, Pay Later’ option, paying $100 to hold the flights.

Like those who already paid in full, Mr Paul received a promising email.

“As a gesture of goodwill, Qantas will be rebooking you in the business class cabin on the same flight for the same price you have already paid,” Qantas Customer Care said.

The email said there was no action required from Mr Paul and he would be sent the updated tickets.

But after no further updates, Mr Paul says he discovered four days later that the total payment due had increase from $17,465 to $100,121.

The airline promised to rebook passengers in business class at no additional cost “as a gesture of good will”.

He told news.com.au it was “really shocking” but thought it might have been “another price mistake”.

Mr Paul said he immediately called Qantas, which was the beginning of a “frustrating” week of multiple phone calls with different customer service representatives.

“It’s really terrible because unfortunately every person I speak to gives a totally different story,” he said.

“They have no consistency in what [information] they are giving.”

He said some representatives promised a solution that didn’t eventuate, while others were confused and unable to assist.

He said he was eventually told to lodge a complaint form and did so, before receiving a call last Friday asking if he wanted to pay $56,000 for the business class flights.

Mr Paul said he would have understood if he had simply been informed there was a price mistake and they were not able to honour it under the terms and conditions of the sale. He said he would have accepted a refund on his deposit.

“That would have been the end of the story,” he said.

But it has been the varying stories from staff who were unable to answer questions about whether they even knew about the website error that left him “really frustrated,” he said.

The issue remained unresolved for two weeks until news.com.au contacted the airline about this story on Tuesday.

He told news.com.au it was “really shocking” but thought it might have been “another price mistake”.

Qantas has promised to provide business class seats at the original price of $4,366.14 per person.

“We apologise to Mr Paul for the trouble and are contacting him to resolve the outstanding issues with his booking,” a Qantas spokesman said.

“As per other customers who attempted to book the First Class fares published in error, we will rebook his flight into Business at no additional cost or provide a full refund.”

News.com.au understands Qantas is unaware of any other processing errors and all other affected bookings have been updated with new tickets, including those who used ‘Book Now, Pay Later’.

Last month, the Qantas Group posted an underlying profit before tax of $2.08 billion for the 2023-24 financial year, down 16 per cent on the year prior.

It was the company’s first full year results with Vanessa Hudson at the helm after she took over the top job in September when Mr Joyce brought forward his retirement two months early so the airline could “move ahead with its renewal” under new management.

The new chief executive described the results as “strong” but acknowledged they were lower, attributing the drop to lower airfares and lower freight revenue, as well as greater investment in customers ($230 million).

Ms Hudson said it was crucial to “get the balance right” between customer and employee satisfaction, and delivering for shareholders.

She said both Qantas and budget airline Jetstar had seen “significant uplift in satisfaction”.

The airline will be pay about $20 million in compensation to customers affected by its flight cancellation policy, after admitting it had misled passengers. This is in addition to a $100 million civil penalty.AFP via Getty Images

When Ms Hudson became CEO, she promised to put customers first in efforts to repair the airline’s reputation.

Earlier this month it was revealed Mr Joyce would have his bonuses slashed by more than $9 million and that the airline had committed to implementing all 23 recommendations made in its review of key governance matters.

Mr Joyce’s bonuses were withheld amid mounting pressure from investors following a string of controversies, including the illegal sacking of 1700 workers, the selling of tickets on already cancelled flights and allegations of anti-competitive behaviour.

The airline will be pay about $20 million in compensation to customers affected by its flight cancellation policy, after admitting it had misled passengers. This is in addition to a $100 million civil penalty.

The Australian Competition and Consumer Commission (ACCC) had launched legal action against the airline in August 2023, claiming it sold tickets for 8000 “ghost flights” (already-cancelled flights) between May and July 2022.