Re-directing after being hacked

Hi,

I help run https://www.cornellschoolofdance.co.uk.

The site appeared to get hacked about a week ago where we couldn’t get in to wp-admin and it came up saying something along the lines of PHPremoteview.

I managed to sort this thanks to the forum, but now, two random .php files have materialised and now when I log in to the site, it redirects to a random site after about 3 seconds. I’ve deleted these random .php files only for them to re-appear.

HELP!!