This has nothing to do with virgin media it's to do with Xbox live server's and where they are based let me explain.
Xbox live has 2 data centre's available one in Ireland and the other in the Netherlands's so this is the reason for high latency Microsoft fully understand this issue so they are opening 2 new data centre's based in the UK on in London and the other has not been disclosed yet but once these come on-line we should see the latency come down more and then have better ping's with in multilayer.
Indeed , which is why in game pings are a lot lower , OP is referring to the ping result in detailed network statistics which doesn't ping a European azure centre but pings one in Seattle , which is why we get pings of 155 or higher
Thanks for posting, I'm sorry to hear of the problems that you are experiencing with your Xbox connection. There are problems showing with your power levels which will affect your connection, we will need to get these levels adjusted by organising an engineer visit.
I can also see that there is a fault ticket open for peak time contention ( F003426516) with a review date estimated for 24/02/2016.
I will send you a private message to arrange an engineer visit.