Not sure if this is the right forum as it's a general issue. Would be good to get some advice on here as your call centres are a nightmare..
I've had Virgin (and Blueyonder/Telewest) at a few addresses in the past and never had any issues and always been satisfied.
I have the 'up to 100MB' at my new address since June and I've constantly had problems with it. Mainly gaming on my Xbox 360 but more recently with my TV signal 'breaking up' and sometimes cutting out completely telling me to call 150. It seems to be getting worse as time goes on.
I have UPnP enabled on my hub and the firewall turned off. Port forwarding is set up for the Xbox Live ports to my 360 IP but I guess it isn't this anyway since the TV is also affected.
I'm sorry to hear you're suffering latency and packet loss on your connection. I've checked the hub stats and network segment for your connection, everything looks OK in general. Do you notice the problems, or are things worse at any particular times of day? Do you have your Xbox 360 connected to the hub or wired or wirelessly? If it's wireless, could you give it a wired test please?
Regarding the TV issues, your TV service connects to a different part of the network to the broadband. I'd suggest popping another thread in our TiVo® boards so one of the TV guys can take a look at the box and the cable to see if there's a separate problem.