i never answer any security questions over the phone. did they read you your social security number? or did they ask you to "verify" it and say that "yes, you read to them what they already had written down"... if they read me my SSN, i still play it cagey and don't verify for them that it is correct. if they are legit, they should snail mail you all of the details at your request, including the original creditor so you can verify the information independently.