Thanks I'm aware of these solutions and they can't be resolved by those methods.
I do have access to the FTP server however the files are not updated with all the current content on my WP account.
I'm only locked out of WordPress displaying the message Server Error 500.
the FTP server is very old therefore the site is static it's not user friendly like Hostgator or GoDaddy. All the files uploaded there are pretty much a blank a WordPress.
I know when the problem occurred. It happened when I added in a bit of code and updated the Theme functions.php on the Child Theme for StoreFront.
The only message displayed:
Server Error 500
The website encountered an error while retrieving http://www.azuredesigns.co.uk/. It may be down for maintenance or configured incorrectly.