I have received almost a dozen calls from them (and four other numbers they are using 815-566-3404, 713-766-9571, 312-428-9480, 202-369-7887); always the same noisy call center, always operators with very think middle eastern accents.  I finally got one them to give me a mailing address, apparently a PO Box at a FedEx office in Chicago, IL (200 W Jackson Blvd, Chicago IL 60606).  I couldn't get the number because the caller had a very thick accent which was explained later.  He wanted to confirm that I was sending payment to the address, and I told him no it would be a court summons.  Which he laughed and told me to save my time because he and the rest of the callers were in Iraq and immune to the telemarketing laws.

My guess is that this is an overseas scam routing through a hacked exchange server in the United States to make their calls look like they are coming from inside the country.  Any mailing addresses they give are likely set to forward to a single mail drop.