This fix is for Firefox users only.
I managed to find the fault, in my Firefox about:config settings, I had enabled network.http.sendRefererHeader=0 , this stops websites from knowing the last webpage I was on. I enabled this setting, as a security procedure to stop websites tracking me all over the internet.
When I changed this setting back to the default network.http.sendRefererHeader=1 , then the Contact Us button works again. But I searched for a fix as I shouldn't have to lower my security settings just to get this website to work.
And I found an easy work around for this, it's to install a Firefox extension, RefControl. It's found at
https://addons.mozilla.org/en-US/firefox/addon/953 . You need to install this, reload Firefox and then go to Tools -> RefControl Options , then click Add Site, and type in saynoto0870.com . In the Action section, click the Custom: radio button, and type in "1" (without the "") into the text box. Now click OK, and look for the Edit button to the right of the "Default for site's not listed", click it and in the Action section click on the radio button for "Block - send no referer".
This will keep the referer blocked on all other websites, but enable it for Saynoto0870.com. I personally did this and now both the "Contact Us" and also the "Click here to Add an new Telephone number" links work.