JOHANNESBURG – It looked like a steal: $72 for a round-trip business class ticket on South African Airways between Johannesburg and Abu Dhabi.

The online offer, part of a promotional sale at the end of February, was indeed too good to be true.

The airline said Thursday that it erroneously published the incorrect fare and that it was refunding customers who had snapped up the tickets. Some 640 bookings were affected, it said.

A regular ticket on the same route in business class sells for about $3,400, South African Airways said.

“We appreciate the fact that customers would under normal circumstances take advantage of bargains and good travel bargains,” airline spokesman Tlali Tlali said in a statement emailed to The Associated Press. He noted, however, that “underpricing would open us up to legal challenges” in an industry where competition is regulated.

Mohamed Vawda, who had taken advantage of what he thought was a great deal, said he was disappointed in an interview with eNCA, a South African news outlet.

“I want to see them honour the tickets because they took the money, they sent you confirmation,” Wada said.