I'm sorry to hear the two contacts have not received the re-subscribe email. We definitely want to rectify this for you. For security reasons, I encourage you to send us an email at social_support(at)constantcontact(dot)com with your username, the two contacts in question, and a reference to this post and we can investigate it further.
We also have a Deliverability department if you would like to speak with a person directly. They are available 8AM To 10PM EST Monday through Thursday and 8AM to 9PM EST on Fridays. Their direct line is 866-433-8499 for U.S. and 339-222-5900 for International.