These guys are bottom feeding class of collection agencies. The buy old or statute barred debt and using harassment tactics try to collect 10 to 30 cents on the dollar. Of course once you pay anything the debt clock resets to day 1 and then their ambulance chasing lawyers will sue for the rest. The best you can do is contact your state authorities (don't waste time with the feds, they won't do anything but collect data and publish reports) to go after them.