That address is now home to a travel agency.
I strongly suspect that 'The Writing School', in London, has now become 'The Writers Bureau', in Manchester. Contact details are here:
http://www.writersbureau.com/contact-us.htm
That's based upon reading a far from complimentary article, which first appeared in
The Spectator, about a certain Mr E H Metcalfe who seems to be behind both ventures:
http://www.absw.org.uk/correspondence_courses. htm
Since you've already handed over your money it might be worth seeing if you can get anything from the Manchester address. Otherwise my advice would be not to touch it with a bargepole.
Your local further education college will run evening classes which, because of the company and feedback of others, will be far more useful (and much more fun) than anything that Mr E H Metcalfe can offer you.
Chris