I have just had Virgin Broadband & Phone Line installed and activated today, am on the VIVID350 package. On WiFi, couple of meters away from the hub I get download speeds of around 30 to 50 mbps on the laptop and 255 mbps on the iphone. Upstairs the max speed is 10 mbps. The kids and wife are up in arms, as we just ditched BT for slow speeds and went for VM's top package.
I also tried wired connection and got 90 mbps with a cat 5E cable and the callcentre guy said try it again with a cat 6A cable and it should reach 300 mbps.
more detail needed on the network card - look in control centre devices - even if it is a gidabit card it needs to be set to that not 10/100
and ignore offshore - your lan cable is more than good enough - just another poor bit of rubbish from them
you could also post some info
log into hub3 - 192.168.0.1 [or 192.168.100.1 if in modem mode] - DON'T SIGN IN, click - click router status [centre of screen] - and post the downstream and upstream figures - to see those press on the grey buttons/boxes labeled - upstream - downstream
have you split the wifi channels - log in and give them seperate names and turn off smart wifi then run more wifi speed tests on each band