Pretty blue box

I got a birthday present from my step-mother and father in the mail yesterday. At least, I'm assuming it was a birthday present considering the timing of its arrival. There was a pretty blue box inside the mailing package which had their return address on it but no card or anything inside the package saying it was from them. I opened the pretty blue box and found a pretty little blue velvet sack. Inside the pretty little sack I found nothing. That's right, it was empty. I haven't called them yet to let them know I got the pretty blue box and sack. I will follow up after I do. Odd.