Yeah from what I understand they don't need a signature. Similar experience happened when I sent my x-box 360 in for warranty. Viewed the tracking and it said it was delivered, called ups they don't know anything about it, waited a week do pursue it further, turns out Microsoft wrote in the wrong address #24 instead of #25 when they shipped it back, so I went to my neighbor, he asked his kids if they seen a package the kids say no. I was sure his little shit kids now had my xbox, at least it was Microshafts fault because I clearly wrote the return address as #25 blablabla. I just wanted to play some damn vids. About 3 minutes later the neighbor shows up with the box still sealed, it was on his porch for a week!
Anyway I would be ready to cry or kill if 2 snowboards went missing. I wish you the best of luck getting them.