I also have creditors interchange contacting me?

I owe a det to AT&T credit card which was sold to creditors interchange. They contacted me and want to settle for 4400 which I do not have right now. I am enrolled in a debt settlement pgoram and am trying to save the money. I offered to pay them $100.00 a month because that is all I can afford right now and they said no. They said I f I can't come up with the 4400 they will take me to court and a put a lien on my poperty and attach my wages. First, all I own is a car. My house is in my husbands' name, not mine. What should I do?