They are debt collector for hospitals.  When they talk, you cannot understand what their name is or any other information they try to tell you.  Then, they get offended when you can't understand them.  Put an American that speaks good, understandable English on there!!  They call and don't leave a message just like scammers do.  And, I informed them, you call from all of these different numbers and I'm not answering to numbers I don't know.  You should at least identify yourself.