I had someone claiming to be from my bank phone me in relation to certain transactions that actually happened, and like a fool I just answered their questions,

I had someone claiming to be from my bank phone me in relation to certain transactions that actually happened, and like a fool I just answered their questions, without verifying who they were. Later on I called back, to verify that it was someone from the bank who had phoned me. The call-centre person in the bank who answered my call was unable to confirm or deny if someone from the transaction-checking department had actually phoned me, because it was all very confidential.