So there was actually quite a few issues, and upon resolving these issues my IP address has been changed.
So for anyone having issues accessing this site on certain platforms, it's because your machine is using cached DNS settings for the old address. Since we have a new address you will need to refresh the DNS. This should expire in due course time and sort itself out anyway..
They have supplied me with a new router. I've been told it could take up to 10 days for all the changes to propagate through and I must reboot the router then as well. I am told the issues have been identified and are being resolved, which is good news.
Sorry for the inconvenience, hopefully service will be resumed.