I apologize you're not able to use our Shopify integration as easily as you should! This is something we would be happy to investigate further for you. In fact, you mentioned nothing happens when you try to enter the portal - are you seeing any error messages or simply a blank page? Is this happening in more than one browser? These are important details to have along with your shop's URL and even if anything odd happen after you first connected (error message, etc.). In the meantime, if you are still unable access your contacts, as a workaround we suggest exporting contacts as a CSV from Shopify and importing this file into Constant Contact.