It's a collection agency calling in regards to sprint

It is a robocaller that is apparently a skip tracer.  The machine said "I need to contact ...., it is important that I contact ..."  I hung up at that point.  I have had the number they called for over 20 years.  Never heard of the person they were trying to contact.  I don't have any reason to believe they are calling for Sprint, or are even a legitimate debt collector, but rather a scam trying to get personal information.  Do not answer a call from this number.

They keep calling.  I don't answer.  The message says Convergent Outsourcing"a debt collector.  Please return the call at 800 477 5451.  I don't owe any money and I don't know the person they were skip tracing.  This is probably a scam.

If you KNOW you owe no money, or believe the call was from a fake debt collector, please take the time to read this:
http://www.consumer.ftc.gov/articles/0258-fake-debt-collectors

Scammers continue to call.  Sometimes a hangup, sometimes a robo message saying "it is important that I get in touch with Scottie L. Dunbar"  No such person has ever been at this number as I have had it for over 20 years.  My guess is this is a scam and they ask for this same person at every number they call.