(Reuters) -Qantas Airways Ltd on Monday said it will defend itself against Australia's competition regulator's accusations that the flagship carrier sold tickets to thousands of flights after they were after they were cancelled.

Qantas said the Australian Competition and Consumer Commission's (ACCC) case, which accuses it of selling the tickets for flights for more than 48 hours after they were cancelled, does not constitute "fee for no service".

"We acknowledge there were delays ... but crucially, it does not equate to Qantas obtaining a 'fee for no service' because customers were reaccommodated on other flights as close as possible to their original time or offered a full refund," the airline said in a statement on its filing with the Australian Stock Exchange.

"This is consistent with our obligations under consumer law and is what we did during the period the ACCC examined," Qantas said.

The carrier attributes the delays and cancellations to challenges around restarting flying after strict COVID-19 shutdowns as staff shortage and supply chain issues worsened at a time of strong pent-up demand.

The flag carrier has been reeling under legal and regulatory actions, as well as facing negative headlines over job cuts during the pandemic, resulting in growing scrutiny and investor calls for management overhaul.

(Reporting by Sameer Manekar in Bengaluru; Editing by Grant McCool)