How much money did you pay him?
Was there any written contract?
If everything was done orally between the two of you, then civil court may be your only legal recourse.
However, I have a suggestion of how you might go about getting your money back without all the hassle of taking him to court.
First, you don't want to pay him a visit and you don't want him to know your on to his little scam. Don't tell him you have seen his location and don't tell him you have spoke with the hotels.
What you do is contact him and give him the impression you want to do more business with him. Possibly you want to add a new company logo to your add or include a coupon and this type of thing. Something that will obviously mean he will have to add to the artwork or change it in some way. Specifically, a way that will cost you more money and which you are willing to put in his pocket to accomplish this.
Make him drive back out to your restaurant!
The important thing is to be sure that he parks his vehicle on your property. In your parking lot or garage area. Then have him come inside your restaurant to discuss the changes you want in your add.
At some point, either you have to excuse yourself for a minute or have an employee secure the guys vehicle so it can not be driven off of your property. Either lock the gate or block the vehicle in with your own vehicles, just don't damage his vehicle in any way. His vehicle is now your collateral.
Now you can discuss how he will be refunding your money. You should have a witness present to verify your position so if and when he calls the police, you have someone to back up your agreement with him to hold the car as collateral.
Now you just have to pray that the vehicle belongs to him and that it's worth whatever he owes you.
Now you want to do this in a professional manner. You don't want to get angry, threaten him or get violent in any way. Don't raise your voice and get into a shouting match, simply explain what you have uncovered and tell him you know he is scamming you. If he argues with you, then give him the opportunity to contact the hotel manager or whoever his contact is and speak to them with you present and listening to both sides of the conversation.
You can let him know that you have spoke to the detectives and that you would rather not bring the police into this situation if you can simply get your money returned, then there will be no hard feelings. If he agrees to return your money then offer to drive him to his bank or pay for a cab to bring him.
If you handle this situation correctly, even if the police are called, this will be a civil matter and they will not get involved as long as no laws are broken. You may want to speak to a captain or detective at the station beforehand and let them see the evidence, so they know this guy is scamming you and possibly committing fraud and/or some other criminal activity. Chances are anyone who would do this has been in trouble with the law in the past and doesn't want to spend anymore time in criminal court.
If the police see what this guy is doing, they will probably work with you and if they show up, they can ask you if you want to press charges or if the two of you would rather work this out between yourselves. The criminal will probably prefer it if the police are not involved
The worse that can happen, is they make you give the guy his car back.
