Okay, I managed to get it working by changing the IPv6 DNS settings. However, I am extremely disappointed in this VPN and will be requesting a refund via HumbleBundle.
It doesn't work with BBC iPlayer (The BBC site can detect I am using a VPN on all 3 UK based servers)
It doesn't work with Netflix US or Netflix UK (Again, Netflix can detect that I am using a VPN on all servers and limits what I can view)
The number of servers per country is extremely limited and Obviously popular sites such as Netflix have them black listed.
Most importantly, the support here is terrible! I literally had to figure things out on my own and took a huge risk with my system with googling public IPv6 DNS settings and going ahead with implementing them (I'm not very computer savvy and support was essential here!). Verified and trusted IPv6 options should be listed on the page that is copied and pasted in response to everyone here on these forums who have suffered the same issues as I did. Also, after being asked if my Firewall was blocking the software and I responded, Nothing! No further attempts to solve my issue were made despite my further questions.
All in all, this entire experience was tedious and nerve wrecking and at the end of the day, the product didn't perform as expected. I'll be advising people I know to stay clear of Avast products both now and in the future.