Recently active topics in JetBlue tagged with bags

Hey,
I had a rather complicated flight schedule involving an ORD to JFK to SJC. But after opening my bag and looking for my freshly purchased jeans (which were packed in their original shopping bag, tags still on, receipt tucked in there), I couldn't find them.

I know it's hard to prove the contents of a bag to your airline, but how would I file a stolen property report with JetBlue and how would you plan on following up that claim.

Thanks very much,
John O'Day