According to flysas.com:
"When you purchase a ticket online from the SAS website or through the SAS Travel Center, you are always entitled to a full refund within 24 hours of the purchase. However, for tickets purchased less than 24 hours before departure, refunds are only issued up to 12 hours before the flight."

If you buy a ticket 22 before departure, do sms check-in, cancel check-in and then cancel the ticket (at least 12 hours before departure and within 24 hours of buying it), you should be able to do it...