Philips and Cohen have you worked with them

I have worked with Phillips and Cohen. I have settled some debt with them very amicably. They used to handle lots of WaMu debt; but Chase handles that now. They don't usually buy debt that I am aware of, they collect for others. They are likely collecting for Advanta, who does have an aggressive reputation. You need to keep an eye out for when the debt is sent to an actual law firm (Phillips and Cohen is just a debt collector). When you get your first letter from a law firm respond with a debt validation request sent certified return receipt. If they don't respond to that request you can beat them in court. If they respond satisfactorily, find a way to make some sort of payment arrangements.