I know the company...it is Credit Bureau Enterprises and they handle all kinds of accounts. In my case it is a student loan I defaulted on a LONG time ago. But they have all types of accounts including but not limited to medical accounts.
Just remember, if you answer the call and it is for you, it counts as a contact so the clock restarts. I plan to answer next time because I need them to send me the paperwork to file for a disability exemption.