If you type in a particular url and your server is configured to respond to that url without redirecting, then the url is going to stay unchanged.
If you want a request to that url to redirect the user somewhere else, you'll need to either alter index.php to redirect the user:
header("location index");
exit;
Or you'll need to set up some appropriate mod_rewrite directive. Offhand, I don't know what that would look like.