An Adelaide businessman says he was put on hold for 15 hours by Qantas as he tried to confirm his flight.

Andrew Kahn waited on hold on his mobile phone for 15 hours, 40 minutes and one second as he tried to get through to Qantas, Fairfax reports.

Mr Kahn called Qantas at 7:22 p.m. on Wednesday trying to confirm his travel arrangements for a trip to New York on Sunday but gave up at 11:01 a.m. on Thursday after his call was not answered.

"I hung up in the end simply because I had had enough," Mr Kahn told Fairfax.

Mr Kahn said he called back only to be told a code error meant he was not booked on his flight.

He said his experience shows Qantas is disconnected from their customer care and maintained he would not travel with Qantas again.

Qantas told Fairfax it had no record of any caller waiting 15 hours to get through to its customer care centres.

A Qantas spokesman said the airline's average wait time was under a minute and the longest wait time was 17 minutes.

The airline said Mr Kahn's booking had been cancelled due to a system error, but has now been reinstated.

The airline said it was looking into the matter and apologised for any inconvenience caused.