I've managed to fix the problem so I thought I'd put it here in case it is of use to anyone else.
When Wordpress transferred my Wordpress site they 'kindly' deleted a plugin they do not support called W3 Cache. However it didn't uninstall properly and mess up my admin controls.
I had to FTP into my site and manually remove all the elements. Here's a link to a website which explains exactly what you need to remove.