A man who waited more than 4.5 hours on the phone to Air New Zealand says the airline needs to introduce a permanent call-back service.
The company is facing the wrath of customers unable to reschedule and cancel bookings over the phone.
Six Air New Zealand flights into Auckland and four flights out were cancelled yesterday morning alone, as the school holidays began.
At the same time, the airline's call centre wait times averaged at least two hours.
Air New Zealand prevents online changes to some bookings, forcing customers - like Brian Robertson - to call the 0800 number.
Last week he finally cancelled a booking at the customer service desk, after days of calling Air New Zealand and going on hold for hours, as well as failed attempts in-person at the airline's regional airport customer services.
"I ended up four or five times on hold, for over two or three hours when I was travelling, or when I had time I would try."
Then he made his longest call attempt on Saturday, 2 July - but hung up after listening to hold music for nearly five hours through headphones all afternoon.
"I just couldn't wait any longer," he told RNZ.
"It was very frustrating."
He hoped Air New Zealand would offer a permanent call-back service to stop customers spending hours waiting on the line.
"That would be a far better situation. Or even if the people at the airport were trained [to reschedule bookings], I wouldn't mind it to get in the car and drive 10 minutes up the road to Palmerston North Airport and speak to people there that could fix the problem."
He said it was "really easy" to book new flights but "virtually impossible" to cancel those he did not need.
"I think that was probably the most frustrating. They seem to have the spending end good. But not so much the customer support end."
Six-hour wait to rebook
Another traveller, who RNZ agreed not to name, waited nearly six hours on the phone to speak to Air New Zealand customer services on Saturday night when their flight from Christchurch to Auckland, and their partner's, was cancelled.
They also say the airline "desperately needs" a call-back service.
"Along with an automated response telling the caller their position in the queue," they said.
"We were lucky enough to have enough time to wait on the line but not everyone can do that."
But the customer said "it was obviously a frustrating wait and instead of doing something fun on our last night in Christchurch, we ended up driving around and then just sitting at home while waiting".
"I honestly felt bad for the employee who answered our call - he was very helpful but it was clear from the tone of his voice that he was incredibly exhausted as well."
An RNZ employee also spent more than three hours on hold to the call centre late last week.
The airline gave a statement to RNZ saying about one in three customers were now calling before they flew, and calls averaged 50 percent longer than pre-pandemic.
It said it had hired an additional 170 customer service staff this year and would hire another 70 in the "next few months".
But the company accepted it was a "frustrating" time for customers and "stressful" for staff.
RNZ asked why Air New Zealand did not offer customer call-backs, and why it prevented online changes to some bookings - but received no reply.
Customers can check call wait times on the company's travel alerts webpage.
But Air New Zealand is also offering credit to anyone who wishes to cancel their booking, and is wiping change fees, this month.
More than 10,000 customers have opted for this so far.
The airline services 20 domestic destinations and competitor Jetstar services five.
The government currently owns 52 percent of Air New Zealand ordinary shares, and it made a $1.5 billion loan available to support the company's cash reserves through the pandemic.