"After Sales Servicing Dept, Springfiled NJ" Loss/theft of watch!!

Brief scenario: I sent my Tag watch to the ONLY LVMH (Tag Heuer)Service Dept in the US,which is located in Springfield NJ. I mailed it insurred for retail value,priority mail, as well as signature confirmation. I checked online at the USPS web site and delivery confirmation as well as signature confirmation was documented. A few days later I received my damaged,empty package in the mail. Upon contacting the After Sales Service Dept, they stated they had my watch, then called the next day to say they did not. They stated it "was refused and returned to sender due to being empty". This is a complete lie, as the USPS has it documented as delivered. Who would sign receipt for a damaged empty package in the first place?They told me I had to file a claim with the USPS and insisted it was "lost in transit". What type of scam is this??I have contacted the manager of the service dept as well as the VP of this department and they insist it is a postal issue. This is clearly not the case per documentation. I have filed a case with the Better Business Bureau, mail Theft with the Postal Inspector, as well as the USPS(which I was informed would be denied since there is documentaion of delivery etc). I have even faxed my complaint to Tag's Switzerland Corporate headquarters. How can a company with such a reputation have such poor customer service, and deny liability when all documentation has them at fault?? Does anyone have any advice as to other contacts? I even called to question if this indeed was Tag Heuer's service dept because of the poor handling of this situation!! HELP!