I got a message to call back... have no idea who they are and I don't owe anyone

That's because I believe it's a scam...

Got a call from 3608418667   integrity assets.. they left a message then called family and friends within an hour of leaving message for me... when called back asked to talk to supervisor but was told he wasn't around then the person got nasty.. I asked him to email the info to me and he said he couldnt.. if I owe you money then why can't you...

They been calling me trying to reach a friend of mine, so we call back and they said he owes them money and they need him to pay inmediatly thru a credit card, so my friend ask them for their address to send a check but they say they could'nt accept checks only credit or debit card, he told him he did'nt have any credit card so they told him to ask a friend or family member to let him borrow one. They were so desperate to scam  my friend cuz thats all they were trying to do

Did you know it is ILLEGAL to discuss (your friend's) matters with a third party (you)?  Refusing to give the company address & information is also a violation of the FDCPA!
That should tell you plenty about the caller.