You may have a case for wire fraud involving interstate commerce. I would check with a lawyer. Call the FBI. They guy certainly broke some state or federal law if he cheated you out of $1500.
BTW UPS did pay my claim based on pictures I sent them. The trick is unless you have the original package, they will claim improperly packed unless you pay the UPS store to pack it, which I did. Then they can’t use that excuse and have to pay. It costs a little more but on an expensive item well worth it. They also didn't ask for the speakers back. They were dinged on the edges but I patched them up and you can't see any damage unless you go up close and look for it.