As it happened to me 2 years ago when Sterling airways filled for bankruptcy, it's bad luck.
I was coming back from a business trip in Copenhagen airport, when nobody was at the check out and no plan displayed for Sterling. I learnt 10 min later that the company went bankrupt in the afternoon. Only solution to go back home: buy full price a ticket with another company, which I did.
I managed to get some refund later with the Visa/Mastercard guarantee for the Serling ticket that was therefore unused... but the ticket was ~£100 in comparison to the new one which cost £500!
I could have managed better with a travel insurance but I did not have one at that time