My bag never shipped, receipt says it did.

I was never shipped a bag from Timbuk2. I purchased one and a strap pad, but in the mail, only the strap pad showed up. The order tracking number only was for the strap pad, as it weighed .3 pounds on UPS's site. After 8 days, I only got my strap pad with a receipt saying it was all shipped. Where is my bag?