Finnair outplaced their baggage handlers to a temp agency at the end of November. Ever since, they have had all kinds of trouble including a wildcat strike. The official labour dispute has now been settled but the operation is still a mess (it had been messy even before).
It would appear (this is speculation, not a fact) that there is a lot of confusion within Finnair and the baggage handling outfit about who is responsible for what and in addition to bags getting lost, lines of communications and feeling of responsibility have also been lost.
Ninety-six hours without any information sounds awfully bad and pretty strange. With the baggage claim check numbers they should be at least be able to tell you where the baggage is.
Hope your stuff turns up -- and hopefully Finnair does the right thing with compensation without undue trouble. Although, according to the Montreal Convention which governs baggage responsibilities, they are not obligated to give you compensation unless the stuff is delayed at least 21 days and consequently declared lost, which seems very stingy.
Finnair has an online service that should (at least theoretically) help you see where your baggage is. The service is located at:
http://www.worldtracer.aero/filedsp/ay.htm.
Hope this did not completely ruin your Christmas.
Cheers,
T.