I need an address for some pdls

I need to find out the physical address for SJM Marketing so that I can find out if they are licensed in any state and what the laws of that state are. I recently sent them a letter stating that I had overpaid them and that I wanted my account considered paid in full and today I got a reply back stating that they still wanted me to pay 250 or they would turn it over to their collections department so I need to get as much info and then write them back.
Thanks