After 8 years of service, the Icelandic carrier WOW air is shutting down all operations as of today, March 28 2019.
The company essentially announced that passengers won't be reimbursed. If you have a flight booked with WOW air, here are your only options to get your money back:
According to The Guardian, around 50% of insurance policies do not cover for an airline going bankrupt.
Extra flights were scheduled by other companies at special "rescue fare":
Routes: London Luton / Reykjavik Keflavík and London Gatwick / Reykjavik Keflavík
To book: call +44 (0) 330 365 5030
Routes: routes including Paris, London, Copenhagen, Amsterdam, New York and Boston
Price: discount up to 25% until April 8 2019
To book: https://www.norwegian.com/
Routes: Reykjavík - London Luton and Reykjavík - Warsaw
To book: https://wizzair.com/#/rescue
Routes: routes including Amsterdam, Berlin, Brussels, Copenhagen, Dublin, Frankfurt, Glasgow, Hamborg, Helsinki, London, Oslo, Paris, Boston, Edmonton, New York, Toronto and Washington DC.
Price: flat rate of $60 for Europe and $100 for US/Canada (all excluding taxes and fees)
To book: https://www.icelandair.com/support/contact-us/getmehome/
Routes: New York - Paris route
Price: unique fare of $130 from April 6 to April 30 2019, then a discount up to 30% until June 28.
To book: +1 877 496 9889
Note that you will likely be asked a proof of your WOW air reservation to get these discounts.
Read the official announcement on the website of WOW air.