Hi wedeen,
Please be patient, I can not be 24hours on the forum nor working on OSClass.
Anyway, there's a problem with what you are asking for. Not every user has telephone number nor website. Only registered users do. If you allow unregistered users to publish ads on your website, they will not have that information. We have a helper for user data, so you will be able to use it with a little modification.
modify item.php (on your theme folder), Add this on the first line
<?php View::newInstance()->_exportVariableToView('user', User::newInstance()->findByPrimaryKey(osc_item_user_id())); ?>
Some check are required to be placed in order to avoid errors of no-data / no-existing user, but if you only allow registered user to publish ads, it should not fail.
Later, you could access telephone data with the user helper
osc_user_phone();
osc_user_website();