How long is too long to wait on hold? Thirty minutes? One hour? Try 15 hours, 40 minutes and one second.

That's how long Adelaide businessman Andrew Kahn waited on hold on his mobile for Qantas from Wednesday (local time) night to yesterday morning - and his call was never answered.

Mr Kahn phoned Qantas at 7.22pm on Wednesday (local time), trying to confirm his travel arrangements for a trip to New York on Sunday.

He finally hung up at 11.01am yesterday, not having spoken to anyone. Why?

But why wait so long? Well, the recorded message said someone would be with him as soon as possible - ''I wanted to find out what exactly they meant would be as soon as possible.'' And after a certain time, he did not want to give up his spot in the queue. The time on hold would easily allow for a flight from Melbourne to Los Angeles.

Mr Kahn said he called back - only to be told a ''code error'' meant he was not booked on his flight. So what to do for all that time?

''[Apart from] surfing the net and working, I also managed to read Bazerman and Moore's seventh edition of Judgment in Managerial Decision Making - more than 200 pages of advanced master's level reading.''

Mr Kahn said the ordeal ''highlights the organisation being very disconnected from their customer care'' and, after flying at the weekend, he would not travel with Qantas again.

The Age, which did not have to wait quite as long as Mr Kahn for a response from Qantas, was told by the airline that it had no record of any caller waiting 15 hours to get through to its contact centres.

''In fact, our average contact centre wait time during that period was under a minute and the longest wait time was 17 minutes,'' a spokesman said.

"The passenger's booking had been cancelled due to a system error, but has now been reinstated. We are looking into how this could have occurred and apologise for any inconvenience caused."

- The Age