Need some on how to deal with a client?

I am the president of a web design business and recently ran into a problem with one of my clients. This client contracted with us to build a online school website and after the project was completed hired us to create a personal website. Now he has come back and said that he does not like the site and wants us to do it over because he doesn't like it. He has accused us of us several false allegations all of which we can prove are lies through email. He had initially been dealing with my husband, but as the owner I felt I should step in. The problem I am having is that this guy doesn't take me seriously because I am a woman and he doesn't believe I am the owner of the business. He ignores my emails and refuses to speak with me about the situation. Can anyone please give me some tips on how to deal with this situation because while I do have experience dealing with different types of people I have never had someone not take me seriously and won't believe that I am the owner.