Thanks for coming back to me. Unfortunately the IT department have looked at and they advised it cannot be the firewall settings because the laptop works with other providers. I will speak to the again about it.
I am really sorry that you are still experiencing these issues, there are a couple of things that I would like to add, the first being unfortunately virgin, as a company are not able to support VPN in general.
With the situation that you are currently having, It would seem as though there is some issue on the end of the laptop/VPN as all other devices are staying connected.
Have you tried it wired? If you haven't and you can, then try this and see if it becomes more stable. If it does, then it may well be a wireless issue (could be your laptop, could be the VM hub...)
Also, even though you laptop is "locked down" and connects VPN, I believe you should still be able to see your wireless connection and what router it is connected to. If you lose access via VPN and then check your wireless and it's showing connected, no internet or no connection etc then I would again suggest it's either your laptop or the VM hub.
If your IT department is any good (and if they've locked it down, they should be), they should be able to look through the logs on your laptop and the servers to see what's happening and figure it out from there.