Mailchimp Httperror when using Mailchimp

Question

I am trying to add users to a pre-existing list in Mailchimp. I use mailchimp-api-php

This is my code:

       <?php
         //path to mailchimp class
        require_once KL_DIR_PATH . 'admin/email_services/Mailchimp.php';           
        $MailChimp = new Mailchimp(xxxxxxxx);

             $result = $MailChimp->call('lists/members', array(
            'id' => 177xxxx,
            'email' => array('email' => rrr@gmail.com),
            'double_optin' => 0,
            'update_existing' => true,
            'replace_interests' => false,
            'send_welcome' => 0,
            'merge_vars' => array('FNAME' => zzzz, 'LNAME' =>ccc),
            ));
             print_r($result);
          ?>

However, I got the following error

FATAL ERROR: UNCAUGHT EXCEPTION 'MAILCHIMP_HTTPERROR' WITH MESSAGE 'API CALL TO LISTS/MEMBERS FAILED: SSL CERTIFICATE PROBLEM: UNABLE TO GET LOCAL ISSUER CERTIFICATE' IN D:\WAMP\WWW\KUDANILEADS\WORDPRESS\WP-CONTENT\PLUGINS\KUDANILEADS\ADMIN\EMAIL_SERVICES\MAILCHIMP.PHP ON LINE 221