Quoted from GTO:

Here is what I would do if I was the OP:
1. Go to the customer's address in person with your truck, knock on the door, and let them know you're coming to pick up the machine. See what happens.
2. File a report with the police department for GTP (Grand Theft Pinball), as a pinball machine is worth more than a lot of POS cars you see around. Maybe even call the police and ask them to come to the customer's house location while you wait there.
In all seriousness, what have the interactions been with the customer after the chargeback? Calls, emails, in-person visit? Has the OP checked with the police department to see what possible recourse there is?

Quoted from Robotworkshop:

Well, if they moved to Michigan then maybe they did:
detroit.craigslist.org link
Although this looks like a total scam/hoax and not a real machine...