mahmoud-ali
Hi,
Basically, in Joomla you will need to have a menu item so that when you click to open a page, it will redirect to that menu item page.
In this case, you don't have menu item for com_contact on your site so that when you click to open, it shows on homepage.
I just created a menu item called 'Contacts' and you can see that it's showing fine now.
Cheers!