This is a Hospital Collection Service.  This is not a separate collection agency, but rather the hospital trying to collect a debt that you owe them before they turn it over to a collection agency.

Received six calls from this number within the last month or so.

Three out of the six calls hung up on me after I answered the phone. Without saying a word.

The other three calls, informed me they were with Community United Methodist Hospital.

A collection agency. They refused to disclose who they were.