If you suspend your booking while booking online, any ticket can be cancelled within 24 hours. If you don’t pay within 24 hours, it will be automatically cancelled.
If Qatar Airways cancels your flight, you are eligible to apply for a refund for your cancelled flight (or if you prefer, you can take an alternative flight offered to you).
If your flight is severely delayed, you may be eligible for a refund.
In the event of the death or serious illness of the passenger, his companion or close relative, the passenger can cancel the flight and obtain a refund with valid documents.
For tickets issued between September 1, 2020, and July 31, 2021, as long as they are used within 1 year after the ticket issuance date or before December 31, 2021, they can be changed for free (but no refund will be given).
If you are denied boarding due to overbooking, you are eligible for a full refund (you may also be eligible for compensation) this was all about Qatar Airways Cancellation Policy.