Don't get shook up over it Maria,
First off, what state do you live in and if you know what the debt they are collecting is for, when was the last time a payment was made?
If they are not an attorney in your state, they cannot threaten legal action. Seeing as they contacted you by phone, they now have 5 days to send something in writing giving you the 30 day right to dispute the alleged debt. They cannot take your money or assets unless they sued you and got a judgment in court. The threats from them are baseless and are just an attempt to extort money from you.
You came to the right place.