NCO Financial systems keep calling NONSTOP?

Well, this guy from NCO Financial systems keeps calling. I mean every day 1-2 times a day. Today I listened to the whole message and he was talking about how he was going to "make a decision" or have a conversation with my mom (who won't call them back) and that he would rather have a conversation with her to make the decision then make it himselff. I know we are in debt and we might file for bankrupcy, but is this legit? Is he going to take our house away or something? Thanks...