I hope you do get your quilt back. Unfortunately, I had a very similar experience. I shipped my quilt via UPS. Unfortunately, it was misdelivered and not returned.
The lesson I learned from that experience is to have the quilt appraised and insured for the appraised value. Also, make sure the package requires a signature by the recipent. Make sure to get te tracking number and track the package via the internet.
I did get paid for the lost of my quilt. But, I had to go all the way to the CEO of UPS America to get paid.
I pray you have better luck.