Sorry, I just noted that I was a bit thrown off by a typo in the 2nd paragraph of your note. Here's a few more observations that may help.
A. This may be a combination of a host header and page settings issue.
B. It appears that your home page settings are set to <a href="http://rainfordtest.com"> and not to none or page | home (as I'd recommend). This will probably get people back to the correct home page at least. You can check this by doing a view source on the page and search for rainford
C. You probably have a host header issue. There are host headers in two places -- the web server configuration and in DNN. Please ask your ISP to again confirm that both the host headers for the web server and the host headers for DNN are pointed to http://rainford.com
D. btw, that same view source and search for Rainford indicates that you have a hard coded url to the old site in the first paragraph of your home page.
Hope this is more helpful. Good luck!
Call or write if you need more assistance.
David