SOLVED
I used this code:
$wpuser = new WP_User($usrid);
$current_role = c_ws_plugin__s2member_user_access::user_access_role ($wpuser);
if ($current_role !== “s2member_level1”)
$user->set_role(“s2member_level1”);
Updating time:
$iCurrentTime = time();
$sqlQuery3 = “UPDATE wp_usermeta SET meta_value = $iCurrentTime WHERE meta_key = ‘wp_s2member_last_payment_time’ AND user_id = ‘” .$usrid. “‘”;
$iEndTime = strtotime(“+1 month”, $iCurrentTime);
$sqlQuery4 = “UPDATE wp_usermeta SET meta_value = $iEndTime WHERE meta_key = ‘wp_s2member_auto_eot_time’ AND user_id = ‘” .$usrid. “‘”;
Taken from: s2member\includes\classes\paypal-notify-in-subscr-modify-w-level.inc.php
