I am sorry to hear this is happening to you. I did review your account and I see that you spoke with one of our Support reps who appears to have resolved the issue. If that is not the case, however, I would love to be of further assistance.
Where are you trying to change the email type? Is it on the contact's profile page or when you're importing a file of contacts? Is it giving you an option to change but then not comitting to it?
Due to the sensitive nature of email addresses, if you would like to email us at social_support(at)constantcontact(dot)com with your username, an example or two of contacts you have experienced this issue with, and a reference to this post we could look at it further for you.