Site Formatting incorrect when switching over from test site

I have updated a site on a test domain and am now ready for it to go live.

To do so, I made a copy of all the files and put them into a new folder and likewise with the database. When I point the primary domain over to the new folder the site formats completely wrong. I have tried all the usual things such as running a search-replace db script etc but nothing seems to work. Also contacted hosting providers but again they couldn't help they said I need to get hold of a developer.