I recently sold an item (two Jace, the Mind Sculptor foiled cards) for $1050 US, and sent the item with insurance and signature confirmation.
According to the tracking and signature confirmation the item arrived and the buyer say so as well, but he claims the envelope didn't contain anything except a note (I wrapped the cards in question with a note thanking him for the purchase and such).
Since you had insurance file a claim. Read the infor form whoever provided the insurance and see what the procedure is. Seems pretty logical and simple to me.
