user6726's answer about civil action is good, as you appear to have lots of evidence that document-based in terms of bank records, etc. And media shaming would work; but you could be sued in retaliation, even if you're right.
But try calling a prosecutor - such as a county attorney - rather than an arm of law enforcement. The police are always overworked and can be reluctant to try and put a case together for the local prosecutor. Contacting a county attorney is free and doesn't require you to get a lawyer, and it can be a surprisingly effective tactic against a criminal.
A phone call or a detailed letter to the county attorney for the person's county of residence that explains the criminal activity may be the key to getting some movement in the situation. You have lots of hard evidence to hand the attorney about an individual who is committing fraud, and that evidence may make simply make the case for the attorney, as it is documented evidence they can immediately verify and use, either at the county level, or be passed to the district (state) prosecutor.
A loss of $4000 is significant, and may be a felony in that state. But the "$6,000 in products that were not shipped" is intent on the criminals' part and is not a loss to you.
If it is a county with a large population, the attorney will have many assistants who may have time to pursue the case. An attorney for a small county may be looking for an easy case.
And who knows? The attorney's office may already know the person - if it's a county with a small population, or if that person already has a criminal history (which you could research yourself in that county's records) - and that makes the case even easier for the attorney.