Laravel mailChimp package error

I try to use the package http://ift.tt/2eWfCA6 as in examples but i got an error:

ErrorException in Mailchimp.php line 64:
Undefined property: BlueBayTravel\Mailchimp\Facades\Mailchimp::$users

when i try to use: Mailchimp::users(), while i can get a connection via Mailchimp::getDefaultConnection(); mean the package is completely red, what u guess the problem with me here ?

via Chebli Mohamed