It's really Chase. I owe them a bunch of money, so it makes sense that they would call me. If you call back, it says it's Chase and goes through a normal automated system before someone answers. You do know that even major corporate banks like Chase outsource calls to India, right? Hey, no one to blame but myself for owing Chase money that I haven't repaid, but the call is legit. Really.
You would give out your entire Social Security Number to persons unknown? Best to call your local branch or see a personal banker to address any issues on your account. Giving out personal information to unknown parties is very risky. Best to get some verifiable written documentation over the alleged debt.