In case of delay, cancellation and rebooking you will be informed via text message, using the number that has been used when making the booking. In case of further questions you can contact their customer hotline of the responsible airline:
Air Greenland +299 70 12 12 (contact Air Greenland)
Icelandair: +354 50 50 100 (contact Icelandair)
Norlandair: +354 414 6960 (contact Norlandair)