How should I contact Amazon about a package that is 2 weeks late?

I do not know if this is the right subreddit, but I am just looking for a little advice then I'll delete this post.

My fiance ordered 2 mtg cards from Amazon on Dec. 2nd. They have yet to come in and the expected delivery date was Dec. 13th. He is worried that he just lost his money for nothing, which is devastating to him because shipping was at least 3x the cost of the cards.

How should we go about contacting them, and honestly, what would they do? Would they even care or would they just say "Whoops, sorry. Whatever."