Facebook scraping my old site design

Hopefully someone here can help! I’m no professional design (as you’ll see) but I have asked this question just about everywhere and no one seems to know what the problem is:

2 months ago I took my old web site down and replaced the homepage with a single index.html page saying the site would be back soon with a new design.
A week ago I launched the new design and all went well.
However, when I try to post the link on my Facebook page, Facebook converts the link to the link of an article on my old site and pulls an image from it. This link no longer exists so if people click on it, they were getting a not found error (until I rerouted the link to my homepage via my site software).
If I go to the debug tool, it says the fetched URL is correct but the canoninical url is the one to the non existant article.
When I click on “See exactly what our scraper sees for your URL” the HTML shown is from my old site design, that does not even exist on my server anymore! I am baffled as to where Facebook is getting this HTML code.
My site host did move me to a new server back in April but they have chacked for me and say they find no problems. Anyone any ideas?
You can recreate the problem by typing www.theprt.co.uk into your status box on facebook and seeing what is actually displayed.
Any help would be MUCH appreciated as this is driving me mad - I cannot promote my new site on my Facebook page.
Thanks in advance for any pointers =)

What’s the status box? I’d like to help, but I have no idea what that means.