Quick update.. end of last week the upstream changed back to how it should be however there was still some packet loss. In the last day or so the packet loss seems to have cleared up, so hopefully it is resolved.
Have you got it sorted out? I have exactly the same problem but i have been facing it for more than half year, last time when this happened in my previous address our family decided to quit from Virgin but i quite like it (when it works)
Constant disconnecting from network and sometimes a huge packet loss - no gaming possible and people start to hate you for ruining their gaming experience.