If you had no idea you were being charged, then you do not owe a red cent.

If the lawyer intended to charge you for the phone call, he or she would have needed to clearly explain that at the outset. If you were told that there would be no charge for consultation time, it would seem that you should not have to pay for asking the question.

Though writing letters is now seen as quaint, they're still darned effective. Consider writing a letter to the lawyer explaining that you never agreed to pay, that no advice was given -- and that you were shocked and surprised to receive the bill. For help in writing these outraged yet oh-so rational letters, see Everybody's Guide to Small Claims Court (Nolo) -- which will come in handy if the lawyer decides to play tough.