Andrew Kahn, a business from Adelaide, in Australia, said he called Qantas at 7.22pm on Wednesday night to confirm travel arrangements for a trip to New York and did not hang up until 11.01am today - having spoken to no one, The Sydney Morning Herald reported.
Mr Kahn said a recorded message replayed constantly, telling him him someone would speak with him ''as soon as possible''.
But as the hours dragged on, in which the Adelaide businessman surfed the net and worked, he finally gave up.
Mr Kahn told Fairfax newspapers that when he called back and finally spoke to an operator, he was told there was no record he was on the flight due an error with his booking.
The operator told him they had "never seen this before" and said a fault led to the message being played on loop, The Sydney Morning Herald reported.
''It is just about the worst customer service any customer could ever receive.''
Qantas said in a statement it had no record of any caller waiting 15 hours.
A Qantas customer service worker offered to reimburse Mr Kahn for the cost of his call if he emailed a copy of his call log, he said.