How to get in touch with yahoo! Answers team?

Today I've got a mail from a certain user called flounder. He or she's writing me referring to a post of mine that I have actually never posted as the topic does not interest me indeed the content of his or her mail hurts my beliefs and feelings. What can I do? Where can I report the intruder? How can I get rid of the intruder? How could this happen at all?