I called the number back, it was certainly not a scam, since they had my debit transaction history (including vendor description and date of purchase) from the past few days. This is information that only my bank or Visa would have. All they were asking was for me to confirm whether I made those purchases [press 1 for yes, 2 for no] and I identified each correctly. The only personal information I entered was the last four digits of my visa card number, which does not give potential "thieves" anything significant.
FYI, they had called me about my PNC Bank Debit card. I'm just hoping that people would stop being so paranoid about this phone call. After reading this board, I was myself scared, especially after observing the high ratio of negative to positive comments. But chill out guys, the company's looking out for your financial well-being, not robbing you.