changed user data

if I loaded the user using
$user = hikashop_loadUser(true);
and then
$user->user_partner_activated = 1;
to activate partner status however the user partnership status is not activated. is there a way to change the attributes of the user object and have them stick

That just set the variable in the object of the current page. It doesn't save the information in the database.
For that, you will have to do like that :

$class = hikashop_get('class.user');
$updateObject = null;
$updateObject->user_id = hikashop_loadUser();
$updateObject->user_partner_activated = 1;
$class->save($updateObject);