Email address already in use

I am trying to change the e-mail for my account but I am getting the error "This email address is already in use."  I used the new e-mail when I placed an order a couple of years ago, but then I deactivated that account with the hope (understanding?) it would release the address so I could use it on my existing account, but I am unable to use it since it is still somehow "in the system."  How do I fix this, or how can I get in contact with a human to help me with this?  Thanks.