If you have no software firewall that could be blocking the site, I think the problem may be with your Internet Service Provider's routing. You'll have to call them up if the problem is on their end.
The problem could also be on Viva-Media's side if they blocked a range of addresses for security reasons (such as someone launching a denial of service attack using that range of addresses).
So you could also try contacting Viva-Media about the problem, though I don't know how quickly they respond to emails. You can try emailing using the email address in the profile of the Viva-Media representative who posted earlier in this thread.
To test if your IP address is mistakenly being blocked, you could try accessing the Viva-Media website with the TOR browser, which changes your IP number. But TOR browser is VERY VERY slow so even if you do get through, it's not something you'd want to continue to use. https://www.torproject.org/