Indigo - Indigo Flight tickets cancelled due to lack of information for transit passengers via Singapore

I had flights booked on **/**/**** with Indigo from Chennai-Trichy-Singapore. Upon arrival to Chennai airport I was advised from Indigo staff that I cannot fly into Singapore as I did not have arrival visa to Singapore and would not be allowed to board the flight and my tickets were cancelled instantly. I had connecting flight from Singapore to Brisbane, which I tried to explain to the staff but in vain. I am an Australian citizen and for passengers transiting via Singapore, there is no requirement for arrival visa. More details can be found https://safetravel.ica.gov.sg/transit/overview
Even though I satisfied all entry eligibility and was travelling via vaccinated travel lane, Indigo staff did not allow me as I did not have any arrival visa to Singapore when I did not need one. All my justification went in vain and had to cancel all my flights with no refund. I had arrangements made with my family back in Brisbane and I am seeking proper justification by Indigo compensating all my losses and mental stress caused due to this incident.