When using the provided php wrapper even using the set example code I keep getting the following error:
Array (  => stdClass Object ( [error_key] => http.status.bad_request [error_message] => Please enter your organization name ) )
There isn't an organization name field anywhere and when I try adding org_name to it it says:
Array (  => stdClass Object ( [error_key] => json.field.invalid [error_message] => #/org_name: Property was found but is not permitted at this location. ) )
I found the solution to this one for anyone else who encounters it. The "Organization Name" field needs to be filled out in constant contact's settings page.