Thank you for bringing this to our attention!
I'm sorry to hear that you are having trouble adding contacts to your account. We will be happy to help you in any way that we can. First, we need a little bit more information. Would you kindly send us an email with a reference to this post and the email addresses of the contacts that you are having trouble adding? We can be reached at social_support(at)constantcontact(dot)com. Once we have this information we will be able to assist you further.