If someone is refusing to leave you alone is there a way to hide from them. Change your identity?

If they are attacking you then moving to a different location will make it hard for them to find you. If you are not in an alliance then you should try to join a strong alliance that can protect you.

It is possible to change your name in the game if you want a different identity but they may still be able to see who you are if they have a record of messages from you.