Are you positive they received it? You have a signed "received" receipt?
The reason I ask is that in my experience, Buck is always very responsive and lightening fast. I purchase knives from the custom shop to honor Scouts earning their Eagle rank, and these custom Bucks get to me in about a week even though they note that it takes four to six weeks for custom orders.
As for sending a knife into Buck for repair, I have never needed to because their product is so good.