Called twice.  Left no message.  Caller ID gave number but no other identification

Person who barely spoke English left message telling me to call the 'very second' I receive the call or 'good luck' to me.  Hmmm, sounds like a threat to my well-being.  I think it's NCO financial calling me at work.  That will stop soon.  I filed grievance with attorney general.  These people work on commission, collecting repayment on debt they purchased from hospitals.  Scum of the earth. If I owe debt I will make arrangements with the person I owe, not some bottom-feeding collection agency.